WO2013065751A1 - Spin oscillation device and manufacturing method for same - Google Patents

Spin oscillation device and manufacturing method for same Download PDF

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Publication number
WO2013065751A1
WO2013065751A1 PCT/JP2012/078199 JP2012078199W WO2013065751A1 WO 2013065751 A1 WO2013065751 A1 WO 2013065751A1 JP 2012078199 W JP2012078199 W JP 2012078199W WO 2013065751 A1 WO2013065751 A1 WO 2013065751A1
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spin
spin oscillation
noise
oscillation
oscillation device
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PCT/JP2012/078199
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French (fr)
Japanese (ja)
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一紀 中田
諭 家形
崇 木村
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国立大学法人九州大学
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F10/00—Thin magnetic films, e.g. of one-domain structure
    • H01F10/32—Spin-exchange-coupled multilayers, e.g. nanostructured superlattices
    • H01F10/324—Exchange coupling of magnetic film pairs via a very thin non-magnetic spacer, e.g. by exchange with conduction electrons of the spacer
    • H01F10/329—Spin-exchange coupled multilayers wherein the magnetisation of the free layer is switched by a spin-polarised current, e.g. spin torque effect
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03B—GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
    • H03B15/00—Generation of oscillations using galvano-magnetic devices, e.g. Hall-effect devices, or using superconductivity effects
    • H03B15/006—Generation of oscillations using galvano-magnetic devices, e.g. Hall-effect devices, or using superconductivity effects using spin transfer effects or giant magnetoresistance
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N50/00—Galvanomagnetic devices
    • H10N50/10—Magnetoresistive devices
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F10/00—Thin magnetic films, e.g. of one-domain structure
    • H01F10/32—Spin-exchange-coupled multilayers, e.g. nanostructured superlattices
    • H01F10/324—Exchange coupling of magnetic film pairs via a very thin non-magnetic spacer, e.g. by exchange with conduction electrons of the spacer
    • H01F10/325—Exchange coupling of magnetic film pairs via a very thin non-magnetic spacer, e.g. by exchange with conduction electrons of the spacer the spacer being noble metal

Definitions

  • the present invention relates to a spin oscillation device using a plurality of spin oscillation elements that self-oscillate magnetization by spin torque.
  • a nonmagnetic layer made of a nonmagnetic material is sandwiched between two ferromagnetic layers made of a ferromagnetic material (a fixed layer and a free layer), and a direct current is applied between the ferromagnetic layers and a magnetic field is applied simultaneously.
  • a spin torque oscillator (ST (N) O: Spin-Torque (Nano) Oscillator) that oscillates a self-excited microwave by rotating the magnetization M has been proposed (see FIG. 11). Although this STNO is very small ( ⁇ 1 ⁇ m) and has a simple structure, since it cannot produce high output, development of a spin oscillation device capable of high output is desired.
  • Patent Document 1 As one method for increasing the output of STNO, for example, as shown in Patent Document 1, a technique for increasing the overall output by providing a plurality of STNOs is disclosed.
  • the technique shown in Patent Document 1 includes a first electrode, a magnetization fixed layer whose magnetization direction is fixed, an intermediate layer, a magnetization free layer capable of changing the magnetization direction, and a second electrode.
  • the microwave oscillation element configured by sequentially stacking, either the magnetization free layer or the second electrode is made of nanoparticles, and a structure in which these are arranged is disclosed.
  • a technique disclosed in Patent Document 2 is disclosed as a technique for synchronizing the phases of a plurality of oscillation elements.
  • the technique disclosed in Patent Document 2 includes a plurality of magnetic elements each having a plurality of magnetic elements sandwiched between a pair of ferromagnetic layers in order to achieve impedance matching in a spin valve element that oscillates at a high frequency.
  • the impedance of the spin valve element is matched to a desired value.
  • a single magnetic domain structure can be realized in each magnetic element without using an advanced lithography method.
  • Non-Patent Document 1 it is disclosed that a phase is synchronized by applying a common pulse current sequence to a plurality of CMOS oscillators. .
  • Non-Patent Document 2 a phenomenon in which oscillations are synchronized by adding white noise to two STNOs.
  • Patent Document 2 is a technique that presupposes a phase locking phenomenon caused by the interaction of high-frequency magnetic fields generated in each element.
  • parameters for example, spin waves, spin vortices, currents
  • impedance matching or the like at the same time, which becomes a large-scale optimization problem and is not easy.
  • the phase locking phenomenon can be optimized, it occurs only under a limited condition of a narrow frequency band and a wide half-value width.
  • Non-Patent Document 2 discloses that two STNOs are synchronized by white noise.
  • in-phase synchronization and anti-phase synchronization occur stochastically, frequency characteristics and output There is a problem that the size is not constant and is insufficient as a practical technique. Further, when the number of STNOs increases, there is a problem that it becomes difficult to add noise common to all STNOs.
  • the present invention provides a spin oscillation device that improves the phase synchronization rate (promotes synchronization) of only a plurality of spin oscillation elements by adding common noise.
  • a nonmagnetic layer made of a nonmagnetic material is sandwiched between two ferromagnetic layers, a fixed layer made of a ferromagnetic material and a free layer, and the nonmagnetic layer and the ferromagnetic layer are sandwiched between them.
  • a plurality of spin oscillating elements that self-oscillate magnetization by applying a spin torque by an applied current, and noise in a frequency band higher than the oscillation frequency of the spin oscillating elements in common with the plurality of spin oscillating elements
  • a control means for controlling the state of magnetization in the free layer of the spin oscillation element and the state of noise added by the noise addition means.
  • noise in a frequency band higher than the oscillation frequency of the spin oscillation element is commonly added to the plurality of spin oscillation elements. Are synchronized, and high-power microwave oscillation can be realized. Further, by controlling the magnetization and noise states in the free layer of the spin oscillation element, the phase synchronization rate of the plurality of spin oscillation elements can be improved, and the phase distribution can be arbitrarily controlled. There is an effect.
  • the trajectory of the precession of the magnetization vector in the free layer when the spin oscillation element vibrates does not cross the axis perpendicular to the magnetization vector in the fixed layer. Control to orbit.
  • the inventors have found that the orbit of the precession of magnetization when the spin oscillation element vibrates is important as a requirement that the phases of the plurality of spin oscillation elements are easily synchronized by noise-induced phase synchronization. That is, in the spin oscillation device according to the present invention, the trajectory of the precession of the magnetization vector in the free layer when the spin oscillation element vibrates across the axis perpendicular to the magnetization vector in the fixed layer. It was shown that a trajectory with no noise is a necessary condition for realizing phase synchronization by noise-induced phase synchronization. With this knowledge, there is an effect that optimization design can be performed for efficiency.
  • control means controls the trajectory of the magnetization precession to a trajectory having an inflection point.
  • the spin oscillation device since the orbit of the precession of magnetization is controlled to an orbit having an inflection point, the phase synchronization by noise-induced phase synchronization is further promoted, There is an effect of improving the synchronization rate.
  • the control means controls the curvature in the vicinity of the inflection point based on the ratio of the harmonic component to the fundamental frequency component.
  • control means determines the characteristics of the inflection point by a parameter relating to a current of the spin oscillation element and / or a parameter relating to a magnetic field.
  • the feature of the inflection point is determined by the parameter regarding the current of the spin oscillation element and / or the parameter regarding the magnetic field. It is possible to obtain a guideline that considers the synchronization of the current and to adjust the synchronization of the phase by the current and / or the magnetic field at the time of control.
  • control means is configured such that the curvature in the vicinity of the inflection point is such that the probability that the spin oscillation element outputs a signal having a reverse phase is equal to or less than a predetermined value. And to adjust the state of noise.
  • the curvature in the vicinity of the inflection point has a probability that the spin oscillation element outputs an antiphase signal below a predetermined value, that is, outputs an antiphase signal.
  • control unit adjusts the parameter and the noise state to the parameter and the noise state obtained based on the phase response derived from the phase reduction method.
  • the parameter and the noise state are controlled to values obtained based on the phase response derived from the phase contraction method.
  • the probability of outputting the above signal can be reduced to 0%, and the spin oscillation element can be controlled to be surely synchronized in phase.
  • the noise adding means includes the plurality of spin oscillation elements, and adds the total output of the specific oscillation frequencies of the plurality of spin oscillation elements as the noise.
  • the output total of the unique oscillation frequencies of the plurality of spin oscillation elements is added as noise.
  • the difference in frequency can be used as noise on the contrary, and the structure can be simplified and an efficient oscillation device can be realized.
  • the noise adding means adds noise by current fluctuation, magnetic field fluctuation, thermal current conversion element, photoelectric element and / or piezoelectric element.
  • the noise is added by the current fluctuation, the magnetic field fluctuation, the thermal current conversion element, the photoelectric element, and / or the piezoelectric element.
  • achieve easily using etc. is produced.
  • control means controls the initial state of magnetization in the free layer of the spin oscillation element so that the magnetization vector directions of the magnetization are aligned.
  • the initial state of magnetization in the free layer of the spin oscillation element is controlled so that the directions of the magnetization vectors are aligned. There is an effect that it becomes possible to do.
  • a nonmagnetic layer made of a nonmagnetic material is sandwiched between two ferromagnetic layers, a fixed layer made of a ferromagnetic material and a free layer, and the nonmagnetic layer and the ferromagnetic layer are sandwiched between them.
  • a plurality of spin oscillating elements that self-oscillate magnetization by applying a spin torque by an applied current, and noise in a frequency band higher than the oscillation frequency of the spin oscillating elements in common with the plurality of spin oscillating elements
  • Noise adding means for adding, and the noise adding means has the plurality of spin oscillation elements, and adds the total output of the oscillation frequencies unique to the plurality of spin oscillation elements as the noise.
  • the noise adding means adds the output sum of the specific oscillation frequencies of the plurality of spin oscillation elements as the noise.
  • the difference in the oscillation frequency inherent to the spin oscillation element can be used as noise, and the structure can be simplified and an efficient oscillation device can be realized.
  • a nonmagnetic layer made of a nonmagnetic material is sandwiched between two ferromagnetic layers, a fixed layer made of a ferromagnetic material and a free layer, and the nonmagnetic layer and the strong magnetic layer are separated.
  • a plurality of spin oscillation elements that self-oscillate magnetization by applying a spin torque by a current passed through the magnetic layer, and a frequency that is higher than the oscillation frequency of the spin oscillation element in common with the plurality of spin oscillation elements
  • a method of manufacturing a spin oscillation device comprising noise adding means for adding noise in a band, wherein a characteristic parameter including at least a parameter relating to physical properties of the spin oscillation element and a noise characteristic of the noise adding means are phase-contracted. Is specified and determined according to the result obtained based on the phase response derived from.
  • the characteristic parameter including at least the parameter relating to the physical property of the spin oscillation element, and the noise characteristic of the noise adding means are phase responses derived from the phase reduction method. Therefore, it is possible to manufacture the spin oscillation device suitable for the specification or purpose of use by accurately determining the characteristics of the spin oscillation element at the design stage. There is an effect.
  • FIG. 1 is a diagram illustrating an overall configuration of a spin oscillation device according to the present embodiment
  • FIG. 2 is a diagram illustrating a standard structure and parameters of a spin oscillation element in the spin oscillation device according to the present embodiment
  • FIG. FIG. 4 is a first diagram showing a result of simulation with the spin oscillation device according to the present embodiment
  • FIG. 4 is a second diagram showing a result of simulation with the spin oscillation device according to the present embodiment.
  • the spin oscillation device 1 includes a spin oscillation element group 12 including a plurality of spin oscillation elements 11 and noise that adds noise in a frequency band higher than the oscillation frequency of the spin oscillation element 11 to the spin oscillation element group 12.
  • An adding unit 13 and a control unit 14 for controlling the state of noise added by the noise adding unit 13 and the state of magnetization of the spin oscillation elements 11 included in the spin oscillation element group 12 are provided. As shown in FIG.
  • the spin oscillation element 11 has a laminated structure in which a spacer made of a nonmagnetic material is sandwiched between a free layer made of a magnetic material and a fixed layer, and a direct current is passed through the laminated structure, By applying spin torque to the magnetization of the free layer, the magnetization self-oscillates.
  • the noise adding means 13 may control the state of noise added by the noise adding means 13 instead of the control means 14.
  • Oscillation characteristics can be controlled by changing the current flowing through the spin oscillation element 11 or the strength of the applied magnetic field, and also realized in a semiconductor by low power supply voltage driving (eg, 0.35 V to 0.25 V). We can expect extremely low power consumption.
  • a spin oscillation element group 12 in which a plurality of spin oscillation elements 11 are provided is used. As described above, by using the spin oscillation element group 12 in which the plurality of spin oscillation elements 11 are arranged in a lattice shape, high output can be realized.
  • the phase difference is diffused, causing a problem that the phases of the spin oscillation elements 11 are not synchronized.
  • the noise adding means 13 adds irregular noise having a frequency higher than the oscillation frequency of the spin oscillation element 11 to the spin oscillation element group 12.
  • the phase synchronization of the plurality of spin oscillation elements 11 included in the spin oscillation element group 12 is promoted by the phenomenon of noise-induced phase synchronization. That is, it is possible to realize high output and phase synchronization by the spin oscillation device 1 according to the present embodiment.
  • the state of noise added by the control means 14 can be controlled to various states such as white noise, brown noise, and pulse, and attributes such as irregularity, intensity, and frequency can be arbitrarily set. It can be controlled.
  • X i is a state vector of the i-th oscillator
  • ⁇ is a noise vector.
  • the states X i are synchronized with each other due to the influence of noise. From a practical point of view, this phenomenon has attracted a great deal of engineering attention.
  • an array of non-coupled non-linear oscillator circuits has been implemented on a silicon substrate and its validity has been demonstrated. From this point of view, general noise-induced phase synchronization can be considered as an STNO synchronization method. Since random magnetic fields and currents are multiplicative noises in STNO dynamics, it is necessary to consider stochastic dynamics, as shown below in general form.
  • ⁇ indicates the intensity of the noise ⁇ (t).
  • the multiplicative noise of the function G (X) causes clustering in which the phase of the oscillator is stochastically distributed due to the noise. Therefore, a model of the STNO array configuration (array) corresponding to this case will be described below.
  • FIG. 2 shows the magnetization dynamics of an uncoupled STNO pair driven by general noise.
  • STNO having the general element configuration shown in FIG. 2 will be described.
  • the dynamics of magnetization in the free layer is given by
  • H H a e x + (H k m x e x ⁇ H dz m z e z ) /
  • the units of the current J and the magnetic fields H a , H k , and H dz are ampere and tesla, respectively.
  • the inventors have found that when the phase synchronization of the spin oscillation element 11 is promoted by noise-induced phase synchronization, the magnetization precession orbit in the spin oscillation element 11 greatly affects.
  • FIG. 3 An example of the simulation result of the above LLGS equation is shown in FIG.
  • the orbital state can be broadly divided into two types: in-plane precession that does not straddle the z-axis and straddles the x-axis, and trajectory that straddles the z-axis and does not straddle the x-axis It is out-of-plane precession.
  • the x-axis and z-axis shown here are the x-axis and z-axis of the spherical coordinate system determined by the magnetization M in the fixed layer of the spin oscillation element 11. That is, the vector direction of the magnetization M is the x axis, and the axis perpendicular to the vector direction of the magnetization M is the z axis.
  • FIG. 4 shows in detail the state of multiple orbits of magnetization m.
  • FIG. 4A shows a trajectory state having no inflection point, and the trajectory when projected onto the plane of ⁇ and ⁇ is a circle or an ellipse. This state is called in-plane small precession.
  • FIG. 4B shows an orbital state having an inflection point. When projected onto the plane of ⁇ and ⁇ , the shape has symmetry as shown in FIG. 4B. This orbital state in FIG. 4B is called in-plane large precession.
  • FIG. 4C shows an out-of-plane precession. In this case, when projected onto the plane of ⁇ and ⁇ , the shape has no symmetry as shown in FIG. 4C. .
  • the reverse phase may also be synchronized.
  • the frequency can be doubled by in-phase synchronization + anti-phase synchronization, but the output value is reduced by that amount, and in-phase synchronization output and in-phase synchronization + anti-phase synchronization output are probable. Control, it becomes difficult to control. Therefore, the case where the inflection rate in the vicinity of the inflection point is very small between FIGS. 4A and 4B is most suitable for realizing in-phase synchronization.
  • the magnitude of the inflection rate near the inflection point is controlled by the ratio of the harmonic component to the fundamental frequency component. That is, with respect to the trajectory having only the fundamental frequency component as shown in FIG. 4A, the phase is more easily synchronized in FIG. 4B including the harmonic component.
  • the optimum harmonic component is included with respect to the fundamental frequency component. (The specific processing for optimization will be described later) is most suitable for realizing in-phase synchronization. By doing so, the precession of magnetization has moderate stability, and noise-induced phase synchronization can realize in-phase synchronization with high probability in a short time, and at the same time realize high output. It becomes possible.
  • phase synchronization in in-plane precession, it is possible to realize phase synchronization by noise-induced phase synchronization, and when there is no inflection point in the trajectory and inflection points with a large inflection rate in the trajectory.
  • phase synchronization can be realized even in some cases, it is most desirable to have a small inflection rate in the vicinity of the inflection point of the orbit in order to reliably realize in-phase synchronization and high output in a short time.
  • the oscillation characteristics can be determined by arbitrarily determining the attenuation constant ⁇ and the spin injection coefficient ⁇ according to the physical properties, and after the design, the noise component By controlling the current J and / or the magnetic field H including the oscillation characteristics, the oscillation characteristics can be controlled.
  • phase synchronization can be realized in a short time.
  • the synchronization probability due to noise-induced phase synchronization can be determined by whether the oscillation phase distribution in the steady state is unimodal or bimodal (Reference 1: Yuya Nakao, Kensuke Arai, Hiroshi Kawamura). , “Noise-induced synchronization and clustering in ensembles of uncoupled limit-cycle oscillators”, Study Group Life Rhythm and Transducer Network Report, Physical Properties Research 87, pp. 546-549).
  • phase response is derived from the LLGS equation by the following phase contraction method so that the oscillation phase distribution is unimodal, that is, in-phase synchronized, and the parameter set is obtained by back calculation.
  • FIG. 5 is a flowchart showing a design procedure using the phase reduction method.
  • S1 a steady density distribution of phases is assumed (S1).
  • S2 a steady density distribution of phases
  • S2 a phase response function
  • phase response function is determined for a single oscillating element in the arrayed oscillation device.
  • a phase response function of ⁇ period is set (S3).
  • a ⁇ periodic function is required.
  • the trajectory (motion trajectory) corresponding to the desired phase response function is determined (S4).
  • the trajectory for the phase response function is determined. That is, a symmetrical trajectory that optimizes the curvature near the inflection point is determined.
  • the range of device parameters is estimated (S5). As described above, the parameters ⁇ , ⁇ , and ⁇ are set using the LLGS equation.
  • the range of bias conditions is determined (S6). Since the trajectory and the oscillation frequency of the oscillation element can be controlled by setting a bias current and / or an external magnetic field, a range of bias conditions that can obtain desired characteristics is determined.
  • device parameters and bias are determined from the optimized conditions (S7). The device parameters (size, aspect ratio, material, geometric parameter) and bias (current, magnetic field) of the oscillating element are determined from the conditions in which phase synchronization is optimized by the phase reduction method.
  • the above parameters can be set so that the occurrence probability of in-phase synchronization and out-of-phase synchronization can be controlled arbitrarily. In other words, depending on the usage environment, it is possible to generate only in-phase synchronization, or to generate in-phase synchronization and out-of-phase synchronization with half probability, especially in-phase synchronization and out-of-phase synchronization with half probability. When generated, it is possible to realize twice the frequency.
  • control means 14 can control the magnetization state and noise state of the spin oscillation element 11 to improve the phase synchronization rate and control the probability of in-phase synchronization and out-of-phase synchronization.
  • spin oscillation elements corresponding to various situations.
  • FIG. 6 is a diagram illustrating an overall configuration of the spin oscillation device according to the present embodiment.
  • the description which overlaps with the said 1st Embodiment is abbreviate
  • the spin oscillation device has the same configuration as the spin oscillation element group 12 in FIG.
  • the sum of outputs of the oscillation frequencies unique to each spin oscillation element 11 in the spin oscillation element group 12 is added as noise. That is, when a plurality of oscillating elements are arranged on a lattice, the noise adding means 13 is formed by utilizing the fact that the phase difference is diffused due to the difference in the inherent frequency of each element. To do. By doing so, since the spin oscillation device 1 and the noise adding means 13 can be made the same structure, the design and manufacturing process can be simplified and the efficiency can be improved. Logically, the frequency of noise can be controlled according to the number of spin oscillation elements 11 included in the spin oscillation device 1.
  • a spin oscillation element group that functions as an oscillation element and a spin oscillation element group that functions as a noise addition unit are formed in a stacked structure, and function as an oscillation element.
  • the configuration is such that common noise can be added from the spin oscillation element group functioning as noise adding means to the spin oscillation element group to be operated.
  • the oscillation element and the noise adding means can be easily created in the same manufacturing process, and common noise can be appropriately added to all the oscillation elements 11, and synchronization by noise-induced phase synchronization can be achieved. Can be realized.
  • FIG. 7 is a diagram illustrating a configuration of the spin oscillation device according to the present embodiment.
  • the description which overlaps with each said embodiment is abbreviate
  • the noise adding means 13 is configured by a current fluctuation, a magnetic field fluctuation, a thermal current conversion element, a photoelectric element, and / or a piezoelectric element. is there.
  • FIG. 7B shows a configuration example in the case of adding noise using magnetic field fluctuation.
  • a spin oscillation element group 12 composed of a plurality of spin oscillation elements 11 is disposed in the central portion of the substrate, and a coil is wound around the magnetic field to form a magnetic field. Generate noise. By doing so, it is possible to add common noise to the spin oscillation element group 12.
  • the arrangement of the spin oscillation elements 11 may be lattice-shaped or irregular.
  • the Euler-Maruyama scheme was used to simulate the solution of the LLGS equation. This scheme has a relatively high convergence.
  • the simulation was performed using the Mersenne Twister function built into MATLAB as a random number generator.
  • ⁇ 1.0
  • the time step was set to 0.05 to simplify the calculation. In this case, any STNO exhibits in-plane large precession in a steady state.
  • FIG. 8A all the STNOs became in-plane large precession in a steady state, and were synchronized in phase.
  • FIG. 8B in the case of different noise sequences, the anti-phase synchronization was performed.
  • FIG. 9 shows the time evolution of the difference between polar angles ⁇ 1 and ⁇ 2 .
  • FIG. 9A shows the case of in-phase synchronization
  • FIG. 9B shows the case of anti-phase synchronization.
  • each STNO is synchronized under the influence of noise.
  • FIG. 10 shows a phase plane projection diagram for polar angles.
  • 10A is a projection diagram in a transient state in in-phase synchronization
  • FIG. 10B is a projection diagram in a stable state in in-phase synchronization
  • FIG. 10C is a projection diagram in a transient state in anti-phase synchronization
  • FIG. 10D is a projection diagram of the stable state in the anti-phase synchronization. This result shows the convergence of the stochastic synchronization state.
  • the probability that in-phase synchronization and anti-phase synchronization will occur is the same.
  • the in-phase synchronization state occurs with a probability of almost 100% (for example, (Reference 2: D. Li, Y. Zhou, C. Zhou and B. Hu, Phys. Rev. B, 82, 140407 (2010).) (Reference 3: D. Li, Y. Zhou, B. Hu and C. Zhou, Phys. Rev. B, 84, 10, 104414 (2011).)).
  • This means that the current synchronization mechanism functions cooperatively and complementarily with the conventional synchronization mechanism to improve performance.
  • the precession state (see FIG. 4) is obtained. It was shown to depend. This indicates that the probability distribution function of the synchronized state can be controlled by adjusting the parameters ⁇ , ⁇ , J and H a , H k and H dz that determine the precession state.

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Abstract

Provided is a spin oscillation device which adds noise common to a plurality of spin oscillation elements in order to synchronize phases. The present invention is provided with: a spin oscillation element group (12) comprising a plurality of spin oscillation elements (11) wherein a spacer comprising non-magnetic material is sandwiched between 2 ferromagnetic layers comprising ferromagnetic material, and by way of current supplied to the spacer and the ferromagnetic layers, spin torque is exerted in order to generate magnetization by self-oscillation; and noise addition means (13) for adding noise which is common to the plurality of spin oscillation elements (11) and which is of a higher frequency than the oscillation frequency of the spin oscillation elements (11). Furthermore, the trajectory of precession of the magnetization of the spin oscillation elements (11) is controlled by way of physical properties, current and a magnetic field so as to have inflection points such that a small curvature is achieved.

Description

スピン発振装置及びその製造方法Spin oscillation device and manufacturing method thereof
　本発明は、スピントルクにより磁化を自励発振する複数のスピン発振素子を用いたスピン発振装置に関する。 The present invention relates to a spin oscillation device using a plurality of spin oscillation elements that self-oscillate magnetization by spin torque.
　非磁性体からなる非磁性層を強磁性体からなる２つの強磁性層（固定層と自由層）で狭持し、強磁性層間に直流電流を通電すると同時に磁場を加えることで、自由層の磁化Ｍを回転させて自励でマイクロ波を発振するスピントルク発振器（ＳＴ（Ｎ）Ｏ：Ｓｐｉｎ－Ｔｏｒｑｕｅ　（Ｎａｎｏ）　Ｏｓｃｉｌｌａｔｏｒ）が提案されている（図１１を参照）。このＳＴＮＯは、非常に微小（＜１μｍ）で単純な構造であるが、高出力ができないため、高出力が可能なスピン発振素子の開発が望まれている。 A nonmagnetic layer made of a nonmagnetic material is sandwiched between two ferromagnetic layers made of a ferromagnetic material (a fixed layer and a free layer), and a direct current is applied between the ferromagnetic layers and a magnetic field is applied simultaneously. A spin torque oscillator (ST (N) O: Spin-Torque (Nano) Oscillator) that oscillates a self-excited microwave by rotating the magnetization M has been proposed (see FIG. 11). Although this STNO is very small (<1 μm) and has a simple structure, since it cannot produce high output, development of a spin oscillation device capable of high output is desired.
　ＳＴＮＯの出力を上げるための一つの手法として、例えば、特許文献１に示すように、ＳＴＮＯを複数併設して全体の出力を上げる技術が開示されている。特許文献１に示す技術は、第１の電極と、磁化方向が固定された磁化固定層と、中間層と、磁化方向を変化させることのできる磁化自由層と、第２の電極とが、この順に積層されて構成されるマイクロ波発振素子において、前記磁化自由層もしくは前記第２の電極のどちらか一方がナノ粒子からなっており、これらが併設された構造が開示されている。 As one method for increasing the output of STNO, for example, as shown in Patent Document 1, a technique for increasing the overall output by providing a plurality of STNOs is disclosed. The technique shown in Patent Document 1 includes a first electrode, a magnetization fixed layer whose magnetization direction is fixed, an intermediate layer, a magnetization free layer capable of changing the magnetization direction, and a second electrode. In the microwave oscillation element configured by sequentially stacking, either the magnetization free layer or the second electrode is made of nanoparticles, and a structure in which these are arranged is disclosed.
　しかしながら、特許文献１のように複数の発振素子を併設（格子化）した場合、各素子の固有の振動数に差があると、それに起因して位相差が拡散してしまう（位相雑音が大きくなる）という問題がある。そこで、位相同期を促進する機構が望まれている。 However, when a plurality of oscillating elements are provided (latticed) as in Patent Document 1, if there is a difference in the inherent frequency of each element, the phase difference is diffused due to this difference (the phase noise is large). There is a problem that. Therefore, a mechanism that promotes phase synchronization is desired.
　複数の発振素子の位相を同期させる技術として、例えば、特許文献２に示す技術が開示されている。特許文献２に示す技術は、高周波の発振を行うスピンバルブ素子においてインピーダンスマッチングを実現するため、絶縁体または非磁性体からなる中間層を一対の強磁性層により挟持した磁性素子を複数含む並列または直列磁性素子群を、さらに直列または並列につないでスピンバルブ素子を得て、並列と直列とを組み合わせて接続する磁性素子群を用いることにより、スピンバルブ素子のインピーダンスを所望の値にマッチングさせることができ、さらに多孔質膜を利用してスピンバルブ素子を作製することにより、高度なリソグラフィー法を用いることなく、個々の磁性素子に単磁区構造を実現することができるものである。 For example, a technique disclosed in Patent Document 2 is disclosed as a technique for synchronizing the phases of a plurality of oscillation elements. The technique disclosed in Patent Document 2 includes a plurality of magnetic elements each having a plurality of magnetic elements sandwiched between a pair of ferromagnetic layers in order to achieve impedance matching in a spin valve element that oscillates at a high frequency. By connecting a series magnetic element group in series or in parallel to obtain a spin valve element, and using a magnetic element group connected in parallel and in series, the impedance of the spin valve element is matched to a desired value. Furthermore, by producing a spin valve element using a porous film, a single magnetic domain structure can be realized in each magnetic element without using an advanced lithography method.
　一方、雑音誘起位相同期と呼ばれる現象が知られている。これはノイズにより振動の位相が同期する現象であり、例えば、非特許文献１に示すように、複数のＣＭＯＳ発振器に共通のパルス電流列を与えることで、位相が同期することが開示されている。 On the other hand, a phenomenon called noise-induced phase synchronization is known. This is a phenomenon in which the phase of vibration is synchronized by noise. For example, as shown in Non-Patent Document 1, it is disclosed that a phase is synchronized by applying a common pulse current sequence to a plurality of CMOS oscillators. .
　また、発明者らにより、２つのＳＴＮＯに白色雑音を付加することで、それらの発振が同期する現象が開示されている（非特許文献２を参照）。 In addition, the inventors have disclosed a phenomenon in which oscillations are synchronized by adding white noise to two STNOs (see Non-Patent Document 2).
特開２００８－５３９１５号公報JP 2008-53915 A ＷＯ２００９／０５４１８２号公報WO2009 / 054182
　しかしながら、特許文献２に示す技術は、各素子で発生する高周波磁場の相互作用に起因する位相ロッキング現象を前提とした技術である。すなわち、このような直接的な相互作用の効果を高めるためには、各素子間で相互に作用するパラメータ（例えば、スピン波、スピン渦、電流）等を考慮して最適化をする必要があり、また、併せてインピーダンスマッチング等を行う必要があり、大規模最適化問題となり容易ではない。さらに、位相ロッキング現象は、最適化できたとしても狭い周波数帯域と広い半値幅の限られた条件でしか生じない。 However, the technique disclosed in Patent Document 2 is a technique that presupposes a phase locking phenomenon caused by the interaction of high-frequency magnetic fields generated in each element. In other words, in order to increase the effect of such direct interaction, it is necessary to perform optimization in consideration of parameters (for example, spin waves, spin vortices, currents) that interact with each other. In addition, it is necessary to perform impedance matching or the like at the same time, which becomes a large-scale optimization problem and is not easy. Furthermore, even if the phase locking phenomenon can be optimized, it occurs only under a limited condition of a narrow frequency band and a wide half-value width.
　また、非特許文献２には、白色雑音により２つのＳＴＮＯが同期することが開示されているが、現象としては同相同期と逆相同期が確率的に起こっているため、周波数特性や出力の大きさが一定ではなく、実用的な技術としては不十分であるという課題を有する。また、ＳＴＮＯの数が多くなった場合には、全てのＳＴＮＯに共通のノイズを付加することが難しくなってしまうという課題を有する。 Non-Patent Document 2 discloses that two STNOs are synchronized by white noise. However, as a phenomenon, since in-phase synchronization and anti-phase synchronization occur stochastically, frequency characteristics and output There is a problem that the size is not constant and is insufficient as a practical technique. Further, when the number of STNOs increases, there is a problem that it becomes difficult to add noise common to all STNOs.
　本発明は、複数のスピン発振素子に共通のノイズを付加するだけで、それらのスピン発振素子の位相同期率を向上させる（同期を促進する）スピン発振装置を提供する。 The present invention provides a spin oscillation device that improves the phase synchronization rate (promotes synchronization) of only a plurality of spin oscillation elements by adding common noise.
　本発明に係るスピン発振装置は、非磁性体からなる非磁性層が、強磁性体からなる固定層及び自由層の２つの強磁性層で狭持され、前記非磁性層及び前記強磁性層に通電される電流により、スピントルクを作用させて磁化を自励発振する複数のスピン発振素子と、前記複数のスピン発振素子に共通して、当該スピン発振素子の発振周波数よりも高い周波数帯域のノイズを加えるノイズ付加手段と、前記スピン発振素子の前記自由層における磁化の状態及び前記ノイズ付加手段が付加するノイズの状態を制御する制御手段とを備えるものである。 In the spin oscillation device according to the present invention, a nonmagnetic layer made of a nonmagnetic material is sandwiched between two ferromagnetic layers, a fixed layer made of a ferromagnetic material and a free layer, and the nonmagnetic layer and the ferromagnetic layer are sandwiched between them. A plurality of spin oscillating elements that self-oscillate magnetization by applying a spin torque by an applied current, and noise in a frequency band higher than the oscillation frequency of the spin oscillating elements in common with the plurality of spin oscillating elements And a control means for controlling the state of magnetization in the free layer of the spin oscillation element and the state of noise added by the noise addition means.
　このように、本発明に係るスピン発振装置においては、複数のスピン発振素子に、当該スピン発振素子の発振周波数よりも高い周波数帯域のノイズを共通に加えるため、雑音誘起位相同期により、スピン発振素子の位相が同期し、高出力なマイクロ波発振を実現することができる。また、スピン発振素子の自由層における磁化やノイズの状態を制御することで、複数のスピン発振素子の位相同期率を向上させることができると共に、位相の分布を任意に制御することが可能になるという効果を奏する。 As described above, in the spin oscillation device according to the present invention, noise in a frequency band higher than the oscillation frequency of the spin oscillation element is commonly added to the plurality of spin oscillation elements. Are synchronized, and high-power microwave oscillation can be realized. Further, by controlling the magnetization and noise states in the free layer of the spin oscillation element, the phase synchronization rate of the plurality of spin oscillation elements can be improved, and the phase distribution can be arbitrarily controlled. There is an effect.
　本発明に係るスピン発振装置は、前記スピン発振素子が振動する際の前記自由層における磁化ベクトルの歳差運動の軌道を、前記固定層における磁化ベクトルに対して面直方向の軸を跨がない軌道に制御するものである。 In the spin oscillation device according to the present invention, the trajectory of the precession of the magnetization vector in the free layer when the spin oscillation element vibrates does not cross the axis perpendicular to the magnetization vector in the fixed layer. Control to orbit.
　発明者らは、複数のスピン発振素子が雑音誘起位相同期により位相が同期しやすくなる要件として、スピン発振素子が振動する際の磁化の歳差運動の軌道が重要であるという知見を得た。すなわち、本発明に係るスピン発振装置においては、スピン発振素子が振動する際の前記自由層における磁化ベクトルの歳差運動の軌道を、前記固定層における磁化ベクトルに対して面直方向の軸を跨がない軌道にすることが、雑音誘起位相同期による位相の同期実現するための必要条件であることを示した。この知見により、効率化に最適化設計できるという効果を奏する。 The inventors have found that the orbit of the precession of magnetization when the spin oscillation element vibrates is important as a requirement that the phases of the plurality of spin oscillation elements are easily synchronized by noise-induced phase synchronization. That is, in the spin oscillation device according to the present invention, the trajectory of the precession of the magnetization vector in the free layer when the spin oscillation element vibrates across the axis perpendicular to the magnetization vector in the fixed layer. It was shown that a trajectory with no noise is a necessary condition for realizing phase synchronization by noise-induced phase synchronization. With this knowledge, there is an effect that optimization design can be performed for efficiency.
　本発明に係るスピン発振装置は、前記制御手段が、前記磁化の歳差運動の軌道を、変曲点を有する軌道に制御するものである。 In the spin oscillation device according to the present invention, the control means controls the trajectory of the magnetization precession to a trajectory having an inflection point.
　このように、本発明に係るスピン発振装置においては、前記磁化の歳差運動の軌道が、変曲点を有する軌道に制御されるため、雑音誘起位相同期による位相の同期をより促進させて、同期率を向上させるという効果を奏する。 Thus, in the spin oscillation device according to the present invention, since the orbit of the precession of magnetization is controlled to an orbit having an inflection point, the phase synchronization by noise-induced phase synchronization is further promoted, There is an effect of improving the synchronization rate.
　本発明に係るスピン発振装置は、前記制御手段が、前記変曲点近傍での曲率を基本周波数成分に対する高調波成分の比率に基づいて制御するものである。発明者らは、鋭意努力の結果、スピン発振素子の磁化の歳差運動の軌道が変曲点を有し、且つその変曲点近傍における変曲率が微小である場合に、高確率で同相同期に短時間で収束することを実現することを見い出した。すなわち、本発明に係るスピン発振装置においては、変曲点近傍における曲率を基本周波数成分に対する高調波成分の比率に基づいて微小に制御することで、短時間で確実性の高い同相同期を実現することが可能になるという効果を奏する。 In the spin oscillation device according to the present invention, the control means controls the curvature in the vicinity of the inflection point based on the ratio of the harmonic component to the fundamental frequency component. As a result of diligent efforts, the inventors found that when the orbit of the precession of magnetization of the spin oscillation element has an inflection point and the inflection rate in the vicinity of the inflection point is very small, the homology is high with high probability. It was found that it can achieve convergence in a short period of time. That is, in the spin oscillation device according to the present invention, high-reliability in-phase synchronization is realized in a short time by minutely controlling the curvature in the vicinity of the inflection point based on the ratio of the harmonic component to the fundamental frequency component. There is an effect that it becomes possible to do.
　本発明に係るスピン発振装置は、前記制御手段が、前記変曲点の特徴を、前記スピン発振素子の電流に関するパラメータ及び／又は磁場に関するパラメータにより決定するものである。 In the spin oscillation device according to the present invention, the control means determines the characteristics of the inflection point by a parameter relating to a current of the spin oscillation element and / or a parameter relating to a magnetic field.
　このように、本発明に係るスピン発振装置においては、前記変曲点の特徴が、前記スピン発振素子の電流に関するパラメータ及び／又は磁場に関するパラメータにより決定されるため、設計時に雑音誘起位相同期による位相の同期を考慮した指針を得ることができると共に、制御時に電流及び／又は磁場による位相の同期の調整を行うことが可能になるという効果を奏する。 As described above, in the spin oscillation device according to the present invention, the feature of the inflection point is determined by the parameter regarding the current of the spin oscillation element and / or the parameter regarding the magnetic field. It is possible to obtain a guideline that considers the synchronization of the current and to adjust the synchronization of the phase by the current and / or the magnetic field at the time of control.
　本発明に係るスピン発振装置は、前記制御手段が、前記変曲点近傍での曲率が、前記スピン発振素子が逆相の信号を出力する確率が所定の値以下となるように、前記各パラメータ及びノイズの状態を調整するものである。 In the spin oscillation device according to the present invention, the control means is configured such that the curvature in the vicinity of the inflection point is such that the probability that the spin oscillation element outputs a signal having a reverse phase is equal to or less than a predetermined value. And to adjust the state of noise.
　このように、本発明に係るスピン発振装置においては、前記変曲点近傍における曲率が、前記スピン発振素子が逆相の信号を出力する確率が所定の値以下、すなわち逆相の信号を出力する確率が小さくなるように、前記各パラメータ及びノイズの状態が調整されることで、スピン発振素子が逆相で同期することを抑制し、同相同期するように制御することができ、高出力を実現することができるという効果を奏する。すなわち、逆相＋同相で同期した場合は、同相のみで同期した場合に比べて高周波を実現することができるが、その分出力が小さくなってしまう。また、曲率が大きくなりすぎると、逆相＋同相の同期と同相の同期との遷移現象が確率的に生じてしまうため、同相のみで同期するように制御することが望ましい。 As described above, in the spin oscillation device according to the present invention, the curvature in the vicinity of the inflection point has a probability that the spin oscillation element outputs an antiphase signal below a predetermined value, that is, outputs an antiphase signal. By adjusting the parameters and the state of noise so as to reduce the probability, the spin oscillation element can be controlled to be synchronized in the opposite phase and controlled to be synchronized in the same phase. There is an effect that it can be realized. That is, when synchronized in the opposite phase + in-phase, a high frequency can be realized as compared with the case of synchronizing only in the same phase, but the output is reduced accordingly. Moreover, if the curvature becomes too large, a transition phenomenon between reverse phase + in-phase synchronization and in-phase synchronization will occur probabilistically, so it is desirable to control so that only in-phase synchronization occurs.
　本発明に係るスピン発振装置は、前記制御手段が、前記パラメータ及びノイズの状態を、位相縮約法から導出される位相応答に基づいて得られる前記パラメータ及びノイズの状態に調整するものである。 In the spin oscillation device according to the present invention, the control unit adjusts the parameter and the noise state to the parameter and the noise state obtained based on the phase response derived from the phase reduction method.
　このように、本発明に係るスピン発振装置においては、前記パラメータ及びノイズの状態が、位相縮約法から導出される位相応答に基づいて得られる値に制御されるため、スピン発振素子が逆相の信号を出力する確率を０％にすることができ、スピン発振素子が確実に同相同期するように制御することができるという効果を奏する。 As described above, in the spin oscillation device according to the present invention, the parameter and the noise state are controlled to values obtained based on the phase response derived from the phase contraction method. The probability of outputting the above signal can be reduced to 0%, and the spin oscillation element can be controlled to be surely synchronized in phase.
　本発明に係るスピン発振装置は、前記ノイズ付加手段が、前記複数のスピン発振素子を有し、当該複数のスピン発振素子の固有の発振周波数の出力総和を前記ノイズとして付加するものである。 In the spin oscillation device according to the present invention, the noise adding means includes the plurality of spin oscillation elements, and adds the total output of the specific oscillation frequencies of the plurality of spin oscillation elements as the noise.
　このように、本発明に係るスピン発振装置においては、複数のスピン発振素子の固有の発振周波数の出力総和をノイズとして付加するため、元来問題となっている複数のスピン発振素子の固有の発振周波数の違いをノイズとして逆に利用することができ、構造を簡略化して効率のよい発振装置を実現することができるという効果を奏する。また、論理的には、スピン発振素子の数に応じた高周波のノイズを発生させることができるため、高周波の発振素子に対しても適切にノイズを付加することができるという効果を奏する。 As described above, in the spin oscillation device according to the present invention, the output total of the unique oscillation frequencies of the plurality of spin oscillation elements is added as noise. The difference in frequency can be used as noise on the contrary, and the structure can be simplified and an efficient oscillation device can be realized. In addition, logically, it is possible to generate high-frequency noise corresponding to the number of spin oscillation elements, and therefore, it is possible to appropriately add noise to high-frequency oscillation elements.
　本発明に係るスピン発振装置は、前記ノイズ付加手段が、電流変動、磁場変動、熱電流変換素子、光電素子及び／又は圧電素子によりノイズを付加するものである。 In the spin oscillation device according to the present invention, the noise adding means adds noise by current fluctuation, magnetic field fluctuation, thermal current conversion element, photoelectric element and / or piezoelectric element.
　このように、本発明に係るスピン発振装置においては、電流変動、磁場変動、熱電流変換素子、光電素子及び／又は圧電素子によりノイズを付加するため、本発明に係るスピン発振装置を既存の素子等を用いて簡単に実現することができるという効果を奏する。 As described above, in the spin oscillation device according to the present invention, the noise is added by the current fluctuation, the magnetic field fluctuation, the thermal current conversion element, the photoelectric element, and / or the piezoelectric element. The effect that it can implement | achieve easily using etc. is produced.
　本発明に係るスピン発振装置は、前記制御手段が、前記スピン発振素子の前記自由層における磁化の初期状態を、前記磁化の磁化ベクトルの方向が揃うように制御するものである。 In the spin oscillation device according to the present invention, the control means controls the initial state of magnetization in the free layer of the spin oscillation element so that the magnetization vector directions of the magnetization are aligned.
　このように、本発明に係るスピン発振装置においては、スピン発振素子の自由層における磁化の初期状態を、磁化ベクトルの方向が揃うように制御するため、短時間に高確率で同相同期を実現することが可能になるという効果を奏する。 As described above, in the spin oscillation device according to the present invention, the initial state of magnetization in the free layer of the spin oscillation element is controlled so that the directions of the magnetization vectors are aligned. There is an effect that it becomes possible to do.
　本発明に係るスピン発振装置は、非磁性体からなる非磁性層が、強磁性体からなる固定層及び自由層の２つの強磁性層で狭持され、前記非磁性層及び前記強磁性層に通電される電流により、スピントルクを作用させて磁化を自励発振する複数のスピン発振素子と、前記複数のスピン発振素子に共通して、当該スピン発振素子の発振周波数よりも高い周波数帯域のノイズを加えるノイズ付加手段とを備え、前記ノイズ付加手段が、前記複数のスピン発振素子を有し、当該複数のスピン発振素子の固有の発振周波数の出力総和を前記ノイズとして付加するものである。 In the spin oscillation device according to the present invention, a nonmagnetic layer made of a nonmagnetic material is sandwiched between two ferromagnetic layers, a fixed layer made of a ferromagnetic material and a free layer, and the nonmagnetic layer and the ferromagnetic layer are sandwiched between them. A plurality of spin oscillating elements that self-oscillate magnetization by applying a spin torque by an applied current, and noise in a frequency band higher than the oscillation frequency of the spin oscillating elements in common with the plurality of spin oscillating elements Noise adding means for adding, and the noise adding means has the plurality of spin oscillation elements, and adds the total output of the oscillation frequencies unique to the plurality of spin oscillation elements as the noise.
　このように、本発明に係るスピン発振装置においては、ノイズ付加手段が、前記複数のスピン発振素子の固有の発振周波数の出力総和を前記ノイズとして付加するため、元来問題となっている複数のスピン発振素子の固有の発振周波数の違いをノイズとして逆に利用することができ、構造を簡略化して効率のよい発振装置を実現することができるという効果を奏する。また、論理的には、スピン発振素子の数に応じた高周波のノイズを発生させることができるため、高周波の発振素子に対しても適切にノイズを付加することができるという効果を奏する。 As described above, in the spin oscillation device according to the present invention, the noise adding means adds the output sum of the specific oscillation frequencies of the plurality of spin oscillation elements as the noise. The difference in the oscillation frequency inherent to the spin oscillation element can be used as noise, and the structure can be simplified and an efficient oscillation device can be realized. In addition, logically, it is possible to generate high-frequency noise corresponding to the number of spin oscillation elements, and therefore, it is possible to appropriately add noise to high-frequency oscillation elements.
　本発明に係るスピン発振装置の製造方法は、非磁性体からなる非磁性層が、強磁性体からなる固定層及び自由層の２つの強磁性層で狭持され、前記非磁性層及び前記強磁性層に通電される電流により、スピントルクを作用させて磁化を自励発振する複数のスピン発振素子と、前記複数のスピン発振素子に共通して、当該スピン発振素子の発振周波数よりも高い周波数帯域のノイズを加えるノイズ付加手段とを備えるスピン発振装置の製造方法であって、前記スピン発振素子の物性に関するパラメータを少なくとも含む特性パラメータ、及び、前記ノイズ付加手段のノイズ特性を、位相縮約法から導出される位相応答に基づいて得られる結果に応じて特定して決定するものである。 In the method for manufacturing a spin oscillation device according to the present invention, a nonmagnetic layer made of a nonmagnetic material is sandwiched between two ferromagnetic layers, a fixed layer made of a ferromagnetic material and a free layer, and the nonmagnetic layer and the strong magnetic layer are separated. A plurality of spin oscillation elements that self-oscillate magnetization by applying a spin torque by a current passed through the magnetic layer, and a frequency that is higher than the oscillation frequency of the spin oscillation element in common with the plurality of spin oscillation elements A method of manufacturing a spin oscillation device comprising noise adding means for adding noise in a band, wherein a characteristic parameter including at least a parameter relating to physical properties of the spin oscillation element and a noise characteristic of the noise adding means are phase-contracted. Is specified and determined according to the result obtained based on the phase response derived from.
　このように、本発明に係るスピン発振装置の製造方法においては、スピン発振素子の物性に関するパラメータを少なくとも含む特性パラメータ、及び、ノイズ付加手段のノイズ特性を、位相縮約法から導出される位相応答に基づいて得られる結果に応じて特定して決定するため、スピン発振素子の特性を設計の段階で正確に決定して、仕様又は使用目的にあったスピン発振装置の製造を行うことができるという効果を奏する。
As described above, in the method of manufacturing the spin oscillation device according to the present invention, the characteristic parameter including at least the parameter relating to the physical property of the spin oscillation element, and the noise characteristic of the noise adding means are phase responses derived from the phase reduction method. Therefore, it is possible to manufacture the spin oscillation device suitable for the specification or purpose of use by accurately determining the characteristics of the spin oscillation element at the design stage. There is an effect.
第１の実施形態に係るスピン発振装置の全体構成を示す図である。It is a figure which shows the whole structure of the spin oscillation apparatus which concerns on 1st Embodiment. 第１の実施形態に係るスピン発振装置におけるスピン発振素子の標準的な構造とパラメータを示す図である。It is a figure which shows the standard structure and parameter of a spin oscillation element in the spin oscillation apparatus which concerns on 1st Embodiment. 第１の実施形態に係るスピン発振装置でシミュレーションした場合の結果を示す第１の図である。It is a 1st figure which shows the result at the time of simulating with the spin oscillation apparatus which concerns on 1st Embodiment. 第１の実施形態に係るスピン発振装置でシミュレーションした場合の結果を示す第２の図である。It is a 2nd figure which shows the result at the time of simulating with the spin oscillation apparatus which concerns on 1st Embodiment. 第１の実施形態に係るスピン発振装置の設計手順を示すフローチャートである。It is a flowchart which shows the design procedure of the spin oscillation apparatus which concerns on 1st Embodiment. 第２の実施形態に係るスピン発振装置の全体構成を示す図である。It is a figure which shows the whole structure of the spin oscillation apparatus which concerns on 2nd Embodiment. その他の実施形態に係るスピン発振装置の構成を示す図である。It is a figure which shows the structure of the spin oscillation apparatus which concerns on other embodiment. 実施例におけるシミュレーション結果を示す第１の図である。It is a 1st figure which shows the simulation result in an Example. 実施例におけるシミュレーション結果を示す第２の図である。It is a 2nd figure which shows the simulation result in an Example. 実施例におけるシミュレーション結果を示す第３の図である。It is a 3rd figure which shows the simulation result in an Example. 従来知られているスピントルク発振器の構造を示す図である。It is a figure which shows the structure of the conventionally known spin torque oscillator.
　以下、本発明の実施の形態を説明する。本発明は多くの異なる形態で実施可能である。また、本実施形態の全体を通して同じ要素には同じ符号を付けている。 Hereinafter, embodiments of the present invention will be described. The present invention can be implemented in many different forms. Also, the same reference numerals are given to the same elements throughout the present embodiment.
　　（本発明の第１の実施形態）
　本実施形態に係るスピン発振装置について、図１ないし図４を用いて説明する。図１は、本実施形態に係るスピン発振装置の全体構成を示す図、図２は、本実施形態に係るスピン発振装置におけるスピン発振素子の標準的な構造とパラメータを示す図、図３は、本実施形態に係るスピン発振装置でシミュレーションした場合の結果を示す第１の図、図４は、本実施形態に係るスピン発振装置でシミュレーションした場合の結果を示す第２の図である。 (First embodiment of the present invention)
The spin oscillation device according to the present embodiment will be described with reference to FIGS. FIG. 1 is a diagram illustrating an overall configuration of a spin oscillation device according to the present embodiment, FIG. 2 is a diagram illustrating a standard structure and parameters of a spin oscillation element in the spin oscillation device according to the present embodiment, and FIG. FIG. 4 is a first diagram showing a result of simulation with the spin oscillation device according to the present embodiment, and FIG. 4 is a second diagram showing a result of simulation with the spin oscillation device according to the present embodiment.
　本実施形態に係るスピン発振装置１は、複数のスピン発振素子１１を含むスピン発振素子群１２と、スピン発振素子群１２にスピン発振素子１１の発振周波数よりも高い周波数帯域のノイズを付加するノイズ付加手段１３と、ノイズ付加手段１３が付加するノイズの状態や、スピン発振素子群１２に含まれるスピン発振素子１１の磁化の状態を制御する制御手段１４とを備える。スピン発振素子１１は、図１１に示すように、磁性体からなる自由層及び固定層で非磁性体からなるスペーサを挟んだ積層構造を有しており、この積層構造に直流電流を通電し、自由層の磁化にスピントルクを作用させることで磁化が自励発振する。なお、ノイズ付加手段１３が付加するノイズの状態を制御するのは、制御手段１４ではなくノイズ付加手段１３自身が行うようにしてもよい。 The spin oscillation device 1 according to this embodiment includes a spin oscillation element group 12 including a plurality of spin oscillation elements 11 and noise that adds noise in a frequency band higher than the oscillation frequency of the spin oscillation element 11 to the spin oscillation element group 12. An adding unit 13 and a control unit 14 for controlling the state of noise added by the noise adding unit 13 and the state of magnetization of the spin oscillation elements 11 included in the spin oscillation element group 12 are provided. As shown in FIG. 11, the spin oscillation element 11 has a laminated structure in which a spacer made of a nonmagnetic material is sandwiched between a free layer made of a magnetic material and a fixed layer, and a direct current is passed through the laminated structure, By applying spin torque to the magnetization of the free layer, the magnetization self-oscillates. It should be noted that the noise adding means 13 may control the state of noise added by the noise adding means 13 instead of the control means 14.
　スピン発振素子１１に流す電流又は加える磁界の強度を変化させることで、発振特性を制御することが可能になると共に、低電源電圧駆動（例えば、０．３５Ｖ～０．２５Ｖ）により、半導体では実現できない極低消費電力化が期待できる。しかしながら、単体のスピン発振素子１１では高出力化が難しいため、本実施形態においては図１に示すように、複数のスピン発振素子１１が併設されたスピン発振素子群１２を用いる。このように複数のスピン発振素子１１が格子状に配列されたスピン発振素子群１２を利用することで、高出力化を実現することができるが、個々のスピン発振素子１１の固有周波数の差により位相差が拡散し、各スピン発振素子１１の位相が同期しない問題が発生してしまう。 Oscillation characteristics can be controlled by changing the current flowing through the spin oscillation element 11 or the strength of the applied magnetic field, and also realized in a semiconductor by low power supply voltage driving (eg, 0.35 V to 0.25 V). We can expect extremely low power consumption. However, since it is difficult to increase the output of the single spin oscillation element 11, in this embodiment, as shown in FIG. 1, a spin oscillation element group 12 in which a plurality of spin oscillation elements 11 are provided is used. As described above, by using the spin oscillation element group 12 in which the plurality of spin oscillation elements 11 are arranged in a lattice shape, high output can be realized. However, due to the difference in the natural frequency of the individual spin oscillation elements 11. The phase difference is diffused, causing a problem that the phases of the spin oscillation elements 11 are not synchronized.
　本実施形態に係るスピン発振装置１は、ノイズ付加手段１３がスピン発振素子群１２にスピン発振素子１１の発振周波数よりも高い周波数の不規則なノイズを付加する。そうすることで、雑音誘起位相同期の現象により、スピン発振素子群１２に含まれる複数のスピン発振素子１１の位相同期が促進される。すなわち、本実施形態に係るスピン発振装置１により、高出力化と位相同期を実現することが可能となる。なお、制御手段１４により、付加されるノイズの状態は、例えば、ホワイトノイズ、ブラウンノイズ、パルス等の様々な状態に制御することができ、その不規則性、強度、周波数等の属性も任意に制御できるものである。 In the spin oscillation device 1 according to the present embodiment, the noise adding means 13 adds irregular noise having a frequency higher than the oscillation frequency of the spin oscillation element 11 to the spin oscillation element group 12. By doing so, the phase synchronization of the plurality of spin oscillation elements 11 included in the spin oscillation element group 12 is promoted by the phenomenon of noise-induced phase synchronization. That is, it is possible to realize high output and phase synchronization by the spin oscillation device 1 according to the present embodiment. The state of noise added by the control means 14 can be controlled to various states such as white noise, brown noise, and pulse, and attributes such as irregularity, intensity, and frequency can be arbitrarily set. It can be controlled.
　ここで、雑音誘起位相同期について説明する。一般的に、確率的同期は、一般的なノイズが付加された非結合の非線形発振器で起こる。発振器の確率的ダイナミクスは、以下のように示される。 Here, noise-induced phase synchronization will be described. In general, stochastic synchronization occurs with a non-coupled non-linear oscillator with added general noise. The stochastic dynamics of the oscillator is shown as follows:
Figure JPOXMLDOC01-appb-M000001
Figure JPOXMLDOC01-appb-M000001
　ここで、Ｘｉは、ｉ番目の発振器の状態ベクトル、ηは、ノイズのベクトルを示す。この場合、各状態Ｘｉは、ノイズの影響により互いに同期する。実用的な観点から、この現象は工学的に非常に注目を集めている。実際には、非結合の非線形発振器の回路の配列は、シリコン基板上に実装されて、その妥当性は実証されている。このような観点から、一般的な雑音誘起位相同期は、ＳＴＮＯの同期方式として考えることができる。ランダムな磁場と電流は、ＳＴＮＯのダイナミクスにおける乗算的なノイズであるため、一般的な形で以下に示されるように、確率的ダイナミクスを考慮する必要がある。 Here, X i is a state vector of the i-th oscillator, and η is a noise vector. In this case, the states X i are synchronized with each other due to the influence of noise. From a practical point of view, this phenomenon has attracted a great deal of engineering attention. In practice, an array of non-coupled non-linear oscillator circuits has been implemented on a silicon substrate and its validity has been demonstrated. From this point of view, general noise-induced phase synchronization can be considered as an STNO synchronization method. Since random magnetic fields and currents are multiplicative noises in STNO dynamics, it is necessary to consider stochastic dynamics, as shown below in general form.
Figure JPOXMLDOC01-appb-M000002
Figure JPOXMLDOC01-appb-M000002
　ここで、σはノイズη（ｔ）の強度を示す。この場合、関数Ｇ（Ｘ）の乗算的なノイズは、ノイズに起因して、発振器の位相が確率的に分布するクラスタリングを引き起こす。したがって、この場合に対応したＳＴＮＯのアレイ構成（配列）についてのモデルを以下に説明する。 Here, σ indicates the intensity of the noise η (t). In this case, the multiplicative noise of the function G (X) causes clustering in which the phase of the oscillator is stochastically distributed due to the noise. Therefore, a model of the STNO array configuration (array) corresponding to this case will be described below.
　図２に、一般的なノイズで駆動される非結合のＳＴＮＯ対の磁化のダイナミクスを示す。まず、図２に示す一般的な素子構成を持つＳＴＮＯについて説明する。自由層における磁化のダイナミクスは次式で示される。 FIG. 2 shows the magnetization dynamics of an uncoupled STNO pair driven by general noise. First, STNO having the general element configuration shown in FIG. 2 will be described. The dynamics of magnetization in the free layer is given by
Figure JPOXMLDOC01-appb-M000003
Figure JPOXMLDOC01-appb-M000003
　ここで、ｍとＭはそれぞれ自由層、固定層における磁化ベクトル、αはギルバート減衰パラメータ、γは磁気回転比、βは基本定数を含む材料に関するパラメータ、Ｊは固定層から自由層に正の方向に流れる電流である。実効的な磁場は、Ｈ＝Ｈａｅｘ＋（Ｈｋｍｘｅｘ－Ｈｄｚｍｚｅｚ）／｜ｍ｜（Ｈａは外部磁場、Ｈｋは容易軸異方性フィールド、Ｈｄｚは透磁率で正規化された反磁場を示す）で定義される。 Where m and M are the magnetization vectors in the free layer and the fixed layer, α is the Gilbert damping parameter, γ is the gyromagnetic ratio, β is a parameter relating to the material including the basic constant, and J is the positive direction from the fixed layer to the free layer. Current flowing through the The effective magnetic field is H = H a e x + (H k m x e x− H dz m z e z ) / | m | (H a is an external magnetic field, H k is an easy axis anisotropy field, H dz represents a demagnetizing field normalized by magnetic permeability).
　また、ＳＴＮＯ対の動的挙動を検討する。各ＳＴＮＯのダイナミクスは、球面座標系でのＬＬＧＳ方程式（Ｌａｎｄａｕ－Ｌｉｆｔｓｈｉｔｚ－Ｇｉｌｂｅｒｔ－Ｓｌｏｎｃｚｅｗｓｋｉ　ｅｑｕａｔｉｏｎｓ）により記述される。 Also, consider the dynamic behavior of STNO pairs. The dynamics of each STNO is described by an LLGS equation (Landau-Liftshitz-Gilbert-Slonkzewski equations) in a spherical coordinate system.
Figure JPOXMLDOC01-appb-M000004
Figure JPOXMLDOC01-appb-M000004
　ただし、θとφは極角、正規化時間τ＝γｔ／（１＋α２）、変換変数Ｕ＝αＨａ－βＪ、Ｖ＝Ｈａ＋αβＪを用いるものとする。電流Ｊ及び磁場Ｈａ，Ｈｋ，Ｈｄｚの単位は、各々アンペアとテスラである。いずれのＳＴＮＯにおいても、極角はθｉとφｉ（ｉ＝１，２）でそれぞれ表される。 However, θ and φ are polar angles, normalized time τ = γt / (1 + α 2 ), conversion variables U = αH a −βJ, and V = H a + αβJ. The units of the current J and the magnetic fields H a , H k , and H dz are ampere and tesla, respectively. In either STNO, polar angle respectively represented by theta i and φ i (i = 1,2).
　また、発明者らは、雑音誘起位相同期によりスピン発振素子１１の位相同期を促進させる際に、スピン発振素子１１における磁化の歳差運動の軌道が大きく影響するという知見を得た。 Further, the inventors have found that when the phase synchronization of the spin oscillation element 11 is promoted by noise-induced phase synchronization, the magnetization precession orbit in the spin oscillation element 11 greatly affects.
　上記ＬＬＧＳ方程式のシミュレーション結果の一例を図３に示す。図３に示すように、磁界及び／又は電流値に応じて、磁化ｍの軌道が変化する。軌道の状態は２つに大別することができ、ｚ軸を跨らず、ｘ軸に跨った軌道であるｉｎ－ｐｌａｎｅ歳差運動と、ｚ軸に跨がり、ｘ軸に跨らない軌道であるｏｕｔ－ｏｆ－ｐｌａｎｅ歳差運動である。ここで示すｘ軸、ｚ軸は、スピン発振素子１１の固定層における磁化Ｍにより決定される球面座標系のｘ軸、ｚ軸である。すなわち、磁化Ｍのベクトル方向がｘ軸であり、磁化Ｍのベクトル方向に対して面直方向の軸がｚ軸である。 An example of the simulation result of the above LLGS equation is shown in FIG. As shown in FIG. 3, the trajectory of magnetization m changes according to the magnetic field and / or current value. The orbital state can be broadly divided into two types: in-plane precession that does not straddle the z-axis and straddles the x-axis, and trajectory that straddles the z-axis and does not straddle the x-axis It is out-of-plane precession. The x-axis and z-axis shown here are the x-axis and z-axis of the spherical coordinate system determined by the magnetization M in the fixed layer of the spin oscillation element 11. That is, the vector direction of the magnetization M is the x axis, and the axis perpendicular to the vector direction of the magnetization M is the z axis.
　また、図４に、磁化ｍの複数の軌道の状態を詳細に示す。図４（Ａ）は、変曲点を持たない軌道状態であり、θとφの平面上に投射した場合の軌道が円又は楕円となる。この状態をｉｎ－ｐｌａｎｅ　ｓｍａｌｌ歳差運動という。図４（Ｂ）は、変曲点を有する軌道状態であり、θとφの平面上に投射した場合に図４（Ｂ）に示すように対称性を有する形状となる。この図４（Ｂ）の軌道状態をｉｎ－ｐｌａｎｅ　ｌａｒｇｅ歳差運動という。図４（Ｃ）は、ｏｕｔ－ｏｆ－ｐｌａｎｅ歳差運動を示し、この場合θとφの平面上に投射した場合に、図４（Ｃ）に示すように対称性を有さない形状となる。 FIG. 4 shows in detail the state of multiple orbits of magnetization m. FIG. 4A shows a trajectory state having no inflection point, and the trajectory when projected onto the plane of θ and φ is a circle or an ellipse. This state is called in-plane small precession. FIG. 4B shows an orbital state having an inflection point. When projected onto the plane of θ and φ, the shape has symmetry as shown in FIG. 4B. This orbital state in FIG. 4B is called in-plane large precession. FIG. 4C shows an out-of-plane precession. In this case, when projected onto the plane of θ and φ, the shape has no symmetry as shown in FIG. 4C. .
　図４（Ｃ）のｏｕｔ－ｏｆ－ｐｌａｎｅ歳差運動はいまだ実験において観測されていない。それに対してｉｎ－ｐｌａｎｅ歳差運動の場合は、雑音誘起位相同期による位相同期を実現することが可能である。より詳細に説明すると、図４（Ａ）の場合は、磁化の歳差運動の安定性が高いため、雑音誘起位相同期による影響を受け難く、位相同期をするのに時間を要してしまう。一方、図４（Ｂ）の場合は、変曲点近傍の変曲率が大きく対称性を有することから、雑音誘起位相同期の影響を受けた磁化の歳差運動が２つの変曲点に分散し、同相同期に加えて逆相も同期してしまう場合がある。この場合、同相同期＋逆相同期により周波数を倍にすることができるが、その分出力値が小さくなってしまうと共に、同相同期の出力と同相同期＋逆相同期の出力とが確率的に出現してしまうため、制御が難しくなる。したがって、図４（Ａ）と図４（Ｂ）の間で、変曲点近傍の変曲率が微小である場合が最も同相同期を実現するのに適している。 The out-of-plane precession in Fig. 4 (C) has not been observed in the experiment yet. On the other hand, in the case of in-plane precession, it is possible to realize phase synchronization by noise-induced phase synchronization. More specifically, in the case of FIG. 4A, since the stability of the precession of magnetization is high, it is difficult to be influenced by noise-induced phase synchronization, and it takes time to perform phase synchronization. On the other hand, in the case of FIG. 4B, since the inflection rate in the vicinity of the inflection point is large and symmetric, the precession of magnetization affected by the noise-induced phase synchronization is dispersed at two inflection points. In addition to the in-phase synchronization, the reverse phase may also be synchronized. In this case, the frequency can be doubled by in-phase synchronization + anti-phase synchronization, but the output value is reduced by that amount, and in-phase synchronization output and in-phase synchronization + anti-phase synchronization output are probable. Control, it becomes difficult to control. Therefore, the case where the inflection rate in the vicinity of the inflection point is very small between FIGS. 4A and 4B is most suitable for realizing in-phase synchronization.
　変曲点近傍における変曲率の大きさは、基本周波数成分に対する高調波成分の比率により制御される。すなわち、図４（Ａ）のような基本周波数成分のみの軌道に対して、高調波成分が含まれる図４（Ｂ）の方が位相が同期しやすくなる。そして、上述したように、図４（Ａ）と図４（Ｂ）の間で、変曲点近傍の変曲率が微小である場合、すなわち、基本周波数成分に対して最適な高調波成分が含まれる場合（最適化については、具体的な処理を後述する）が最も同相同期を実現するのに適することとなる。そうすることで、磁化の歳差運動が適度な安定性を有し、且つ雑音誘起位相同期により短時間に高確率で同相同期を実現することができ、また同時に高出力を実現することが可能となる。 The magnitude of the inflection rate near the inflection point is controlled by the ratio of the harmonic component to the fundamental frequency component. That is, with respect to the trajectory having only the fundamental frequency component as shown in FIG. 4A, the phase is more easily synchronized in FIG. 4B including the harmonic component. As described above, when the inflection rate in the vicinity of the inflection point is small between FIGS. 4A and 4B, that is, the optimum harmonic component is included with respect to the fundamental frequency component. (The specific processing for optimization will be described later) is most suitable for realizing in-phase synchronization. By doing so, the precession of magnetization has moderate stability, and noise-induced phase synchronization can realize in-phase synchronization with high probability in a short time, and at the same time realize high output. It becomes possible.
　以上のことから、ｉｎ－ｐｌａｎｅ歳差運動の場合に、雑音誘起位相同期による位相同期を実現することが可能であり、軌道に変曲点がない場合及び軌道に大きい変曲率の変曲点がある場合でも位相同期は実現できるが、短時間で同相同期且つ高出力を確実に実現するためには、軌道の変曲点近傍に微小な変曲率を有することが最も望ましい。 From the above, in in-plane precession, it is possible to realize phase synchronization by noise-induced phase synchronization, and when there is no inflection point in the trajectory and inflection points with a large inflection rate in the trajectory. Although phase synchronization can be realized even in some cases, it is most desirable to have a small inflection rate in the vicinity of the inflection point of the orbit in order to reliably realize in-phase synchronization and high output in a short time.
　また、上述したように、スピン発振素子１１の設計時には、その物性により減衰定数α、スピン注入係数βを任意に決定して、発振特性を決めることができると共に、設計後にあっては、ノイズ成分を含む電流Ｊ及び／又は磁場Ｈを制御することで、発振特性を制御することが可能となる。 As described above, when the spin oscillation element 11 is designed, the oscillation characteristics can be determined by arbitrarily determining the attenuation constant α and the spin injection coefficient β according to the physical properties, and after the design, the noise component By controlling the current J and / or the magnetic field H including the oscillation characteristics, the oscillation characteristics can be controlled.
　さらに、スピン発振素子１１の初期状態を、例えば一般的な磁化反転技術により自由層の磁化が同じ方向に揃うようにしておくことで、短時間で位相同期を実現することが可能となる。 Furthermore, by setting the initial state of the spin oscillation element 11 so that the magnetizations of the free layers are aligned in the same direction by, for example, a general magnetization reversal technique, phase synchronization can be realized in a short time.
　さらにまた、位相縮約法から導出される位相応答に基づいて、パラメータやノイズ強度を特定することで、確実な同相同期の実現が可能となる。つまり、雑音誘起位相同期による同期確率は、定常状態における発振位相の分布が単峰性になるか双峰性になるかで判別することができる（参考文献１：中尾裕也，新井賢亮，河村洋史，　「Ｎｏｉｓｅ－ｉｎｄｕｃｅｄ　ｓｙｎｃｈｒｏｎｉｚａｔｉｏｎ　ａｎｄ　ｃｌｕｓｔｅｒｉｎｇ　ｉｎ　ｅｎｓｅｍｂｌｅｓ　ｏｆ　ｕｎｃｏｕｐｌｅｄ　ｌｉｍｉｔ－ｃｙｃｌｅ　ｏｓｃｉｌｌａｔｏｒｓ」，　研究会　生命リズムと振動子ネットワーク　報告，　物性研究　８７，ｐｐ．５４６－５４９，　２００７）。 Furthermore, by specifying parameters and noise intensity based on the phase response derived from the phase contraction method, it is possible to realize reliable in-phase synchronization. In other words, the synchronization probability due to noise-induced phase synchronization can be determined by whether the oscillation phase distribution in the steady state is unimodal or bimodal (Reference 1: Yuya Nakao, Kensuke Arai, Hiroshi Kawamura). , “Noise-induced synchronization and clustering in ensembles of uncoupled limit-cycle oscillators”, Study Group Life Rhythm and Transducer Network Report, Physical Properties Research 87, pp. 546-549).
　発振位相の分布が単峰性、すなわち同相同期するように、上記ＬＬＧＳ方程式から以下に示す位相縮約法により位相応答を導出し、それから逆算してパラメータ集合を得る。 The phase response is derived from the LLGS equation by the following phase contraction method so that the oscillation phase distribution is unimodal, that is, in-phase synchronized, and the parameter set is obtained by back calculation.
Figure JPOXMLDOC01-appb-M000005
Figure JPOXMLDOC01-appb-M000005
　ただし、Ｐは上記各パラメータα，β，γ，Ｈ，Ｊで、Ｉはノイズを含む入力とする。この位相縮約法により導出される位相感受関数Ｚと入力Ｉが結合された位相結合関数（Ｚ（φ）Ｉ（＝位相応答））により、位相分布が単峰性となる同相同期の場合の各パラメータと入力を得ることができる。 However, P is the above parameters α, β, γ, H, J, and I is an input including noise. In the case of in-phase synchronization in which the phase distribution is unimodal by a phase coupling function (Z (φ) I (= phase response)) in which the phase sensitivity function Z derived by this phase reduction method and the input I are combined. Each parameter and input can be obtained.
　図５は、上記位相縮約法を利用した設計手順を示すフローチャートである。まず、位相の定常密度分布を仮定する（Ｓ１）。上記参考文献１に示すように、アレイ状の発振装置の位相同期を同相又は逆相にするためには、位相の定常密度分布を単峰性又は双峰性にすることが必要となる（参考文献１のＦｉｇ２を参照）。このとき、同相同期に対応するのが単峰性であり、異相同期に対応するのが双峰性となる。Ｓ１で定常密度分布が仮定されると、位相応答関数を決定する（Ｓ２）。参考文献１にある理論から、所望の位相密度分布を得るためには、位相応答関数と相乗雑音の畳み込みを計算し、最適化することが必要となる。このとき、アレイ状の発振装置における単体の発振素子について、位相応答関数が決定される。Ｓ２で位相応答関数が決定すると、π周期の位相応答関数となるようにする（Ｓ３）。位相応答関数を最適化するには、π周期関数にすることが必要となる。 FIG. 5 is a flowchart showing a design procedure using the phase reduction method. First, a steady density distribution of phases is assumed (S1). As shown in the above-mentioned reference 1, in order to make the phase synchronization of the arrayed oscillation device in phase or in phase, it is necessary to make the steady density distribution of the phase unimodal or bimodal (reference). (See FIG. 2 of Document 1). At this time, it is unimodal that corresponds to in-phase synchronization, and bimodal that corresponds to out-of-phase synchronization. When a steady density distribution is assumed in S1, a phase response function is determined (S2). In order to obtain a desired phase density distribution from the theory in Reference 1, it is necessary to calculate and optimize the convolution of the phase response function and the synergistic noise. At this time, a phase response function is determined for a single oscillating element in the arrayed oscillation device. When the phase response function is determined in S2, a phase response function of π period is set (S3). In order to optimize the phase response function, a π periodic function is required.
　Ｓ３で位相応答関数がπ周期になると、所望の位相応答関数に対応する軌道（運動軌道）を決定する（Ｓ４）。位相応答関数がπ周期となるためには、軌道が対称性を持つようにすることが必要であり、同時に、位相の密度分布を最適化する条件として、時間波形の基本周波数成分と高調波成分の比率を調整する必要があり、所望の時間波形を生成する軌道を決定する。すなわち、変曲点近傍の曲率を最適化するような対称軌道を決定する。 When the phase response function reaches π period in S3, the trajectory (motion trajectory) corresponding to the desired phase response function is determined (S4). In order for the phase response function to have a π period, it is necessary to make the trajectory symmetrical, and at the same time, as a condition for optimizing the phase density distribution, the fundamental frequency component and the harmonic component of the time waveform The trajectory for generating the desired time waveform is determined. That is, a symmetrical trajectory that optimizes the curvature near the inflection point is determined.
　Ｓ４で軌道が決定されると、デバイスパラメータの範囲を見積もる（Ｓ５）。上述したように、ＬＬＧＳ方程式を用いてパラメータα、β及びγを設定する。Ｓ５でデバイスパラメータが決まると、バイアス条件の範囲を決定する（Ｓ６）。発振素子の軌道及び発振周波数は、バイアス電流及び／又は外部磁場を設定することで制御できるので、所望の特性が得られるようなバイアス条件の範囲を決定する。Ｓ６でバイアス条件の範囲が決定すると、最適化した条件から、デバイスパラメータ及びバイアスを決定する（Ｓ７）。位相縮約法により位相同期を最適化した条件から、発振素子のデバイスパラメータ（サイズ、アスペクト比、材料、幾何学的パラメータ）及びバイアス（電流、磁場）を決定する。 When the orbit is determined in S4, the range of device parameters is estimated (S5). As described above, the parameters α, β, and γ are set using the LLGS equation. When the device parameters are determined in S5, the range of bias conditions is determined (S6). Since the trajectory and the oscillation frequency of the oscillation element can be controlled by setting a bias current and / or an external magnetic field, a range of bias conditions that can obtain desired characteristics is determined. When the range of bias conditions is determined in S6, device parameters and bias are determined from the optimized conditions (S7). The device parameters (size, aspect ratio, material, geometric parameter) and bias (current, magnetic field) of the oscillating element are determined from the conditions in which phase synchronization is optimized by the phase reduction method.
　なお、同相同期と異相同期の発生確率を任意に制御できるように、上記パラメータを設定することも可能となる。すなわち、使用環境に応じて、同相同期のみを発生させたり、同相同期と異相同期とを半々の確率で発生させることが可能であり、特に同相同期と異相同期とを半々の確率で発生させた場合は、２倍の周波数を実現することが可能となる。 Note that the above parameters can be set so that the occurrence probability of in-phase synchronization and out-of-phase synchronization can be controlled arbitrarily. In other words, depending on the usage environment, it is possible to generate only in-phase synchronization, or to generate in-phase synchronization and out-of-phase synchronization with half probability, especially in-phase synchronization and out-of-phase synchronization with half probability. When generated, it is possible to realize twice the frequency.
　以上のように、制御手段１４が、スピン発振素子１１の磁化の状態やノイズの状態を制御することで、位相同期率を向上させたり、同相同期と異相同期の確率を制御することができ、様々な状況に対応するスピン発振素子の実現が可能になる。 As described above, the control means 14 can control the magnetization state and noise state of the spin oscillation element 11 to improve the phase synchronization rate and control the probability of in-phase synchronization and out-of-phase synchronization. Thus, it is possible to realize spin oscillation elements corresponding to various situations.
　　（本発明の第２の実施形態）
　本実施形態に係るスピン発振装置について、図６を用いて説明する。図６は、本実施形態に係るスピン発振装置の全体構成を示す図である。なお、本実施形態において前記第１の実施形態と重複する説明は省略する。 (Second embodiment of the present invention)
The spin oscillation device according to the present embodiment will be described with reference to FIG. FIG. 6 is a diagram illustrating an overall configuration of the spin oscillation device according to the present embodiment. In addition, in this embodiment, the description which overlaps with the said 1st Embodiment is abbreviate | omitted.
　本実施形態に係るスピン発振装置は、図６（Ａ）に示すように、前記第１のスピン発振装置において、ノイズ付加手段１３が、図１におけるスピン発振素子群１２と同様の構成を有しているものであり、スピン発振素子群１２における各スピン発振素子１１の固有の発振周波数の出力総和をノイズとして付加するものである。すなわち、複数の発振素子を格子上に配列した場合に、各素子の固有の振動数に差があることで位相差が拡散してしまうことを逆に利用することで、ノイズ付加手段１３を形成する。そうすることで、スピン発振装置１とノイズ付加手段１３を同じ構造とすることができるため、設計、製造の工程を簡素化して効率化を図ることができる。また、論理的にはスピン発振装置１に含まれるスピン発振素子１１の数に応じてノイズの周波数を制御することができる。 As shown in FIG. 6A, the spin oscillation device according to the present embodiment has the same configuration as the spin oscillation element group 12 in FIG. The sum of outputs of the oscillation frequencies unique to each spin oscillation element 11 in the spin oscillation element group 12 is added as noise. That is, when a plurality of oscillating elements are arranged on a lattice, the noise adding means 13 is formed by utilizing the fact that the phase difference is diffused due to the difference in the inherent frequency of each element. To do. By doing so, since the spin oscillation device 1 and the noise adding means 13 can be made the same structure, the design and manufacturing process can be simplified and the efficiency can be improved. Logically, the frequency of noise can be controlled according to the number of spin oscillation elements 11 included in the spin oscillation device 1.
　具体的な構成として、例えば図６（Ｂ）に示すように、発振素子として機能させるスピン発振素子群と、ノイズ付加手段として機能させるスピン発振素子群とを積層構造で形成し、発振素子として機能させるスピン発振素子群に、ノイズ付加手段として機能させるスピン発振素子群から共通のノイズを付加することできるような構成とする。こうすることで、発振素子とノイズ付加手段を同一の製造工程で容易に作成することができると共に、全ての発振素子１１に共通のノイズを適切に付加することができ、雑音誘起位相同期による同期を実現することができる。 As a specific configuration, for example, as illustrated in FIG. 6B, a spin oscillation element group that functions as an oscillation element and a spin oscillation element group that functions as a noise addition unit are formed in a stacked structure, and function as an oscillation element. The configuration is such that common noise can be added from the spin oscillation element group functioning as noise adding means to the spin oscillation element group to be operated. In this way, the oscillation element and the noise adding means can be easily created in the same manufacturing process, and common noise can be appropriately added to all the oscillation elements 11, and synchronization by noise-induced phase synchronization can be achieved. Can be realized.
　　（その他の実施形態）
　本実施形態に係るスピン発振装置について、図７を用いて説明する。図７は、本実施形態に係るスピン発振装置の構成を示す図である。なお、本実施形態において前記各実施形態と重複する説明は省略する。 (Other embodiments)
The spin oscillation device according to the present embodiment will be described with reference to FIG. FIG. 7 is a diagram illustrating a configuration of the spin oscillation device according to the present embodiment. In addition, in this embodiment, the description which overlaps with each said embodiment is abbreviate | omitted.
　本実施形態に係るスピン発振装置は、図７（Ａ）に示すように、ノイズ付加手段１３が、電流変動、磁場変動、熱電流変換素子、光電素子及び／又は圧電素子等により構成させるものである。図７（Ｂ）に、磁場変動を利用してノイズを付加する場合の構成例を示す。磁場変動を利用する場合は、図７（Ｂ）に示すように、基板の中央部分に複数のスピン発振素子１１からなるスピン発振素子群１２を配設し、その周囲にコイルを巻回して磁界によるノイズを発生させる。そうすることで、スピン発振素子群１２に共通のノイズを付加することが可能となる。 In the spin oscillation device according to the present embodiment, as shown in FIG. 7A, the noise adding means 13 is configured by a current fluctuation, a magnetic field fluctuation, a thermal current conversion element, a photoelectric element, and / or a piezoelectric element. is there. FIG. 7B shows a configuration example in the case of adding noise using magnetic field fluctuation. When using magnetic field fluctuation, as shown in FIG. 7B, a spin oscillation element group 12 composed of a plurality of spin oscillation elements 11 is disposed in the central portion of the substrate, and a coil is wound around the magnetic field to form a magnetic field. Generate noise. By doing so, it is possible to add common noise to the spin oscillation element group 12.
　なお、前記各実施形態において、スピン発振素子１１の配置は、格子状であっても不規則であってもよい。単位面積あたりの素子数を最大化する場合には、正方格子状又は六角格子状とするのが望ましい。また、スピン交換相互作用のように、近接されたスピン発振素子１１間の相互作用を考慮する場合は、それぞれの相互作用を均一化するために規則的に配置されることが望ましい。 In each of the embodiments described above, the arrangement of the spin oscillation elements 11 may be lattice-shaped or irregular. When maximizing the number of elements per unit area, it is desirable to use a square lattice or hexagonal lattice. Further, when considering the interaction between the adjacent spin oscillation elements 11 like the spin exchange interaction, it is desirable to arrange them regularly in order to make each interaction uniform.
　以下に、第１の実施形態に示したＬＬＧＳ方程式のシミュレーション結果を示す。数値シミュレーションを使用することにより、白色雑音を加えた場合の図２に示す各ＳＴＮＯの動作（ダイナミクス）について説明する。 The simulation result of the LLGS equation shown in the first embodiment is shown below. The operation (dynamics) of each STNO shown in FIG. 2 when white noise is added will be described using numerical simulation.
　ＬＬＧＳ方程式の解をシミュレーションするために、Ｅｕｌｅｒ－Ｍａｒｕｙａｍａスキームを用いた。このスキームは、相対的に高い収束性を持っている。乱数発生器としてＭＡＴＬＡＢに組み込まれたメルセンヌ・ツイスタ関数を使用してシミュレーションを行った。各パラメータは、α＝０．０１、β＝１．０、Ｈａ＝０．２、Ｈｋ＝０．０１、Ｈｄｚ＝１．６、Ｊ＝０．０１とした。また、γ＝１．０とし、タイムステップは、計算の簡略化のために０．０５に設定した。この場合、いずれのＳＴＮＯも定常状態でｉｎ－ｐｌａｎｅ　ｌａｒｇｅ歳差運動を示す。 The Euler-Maruyama scheme was used to simulate the solution of the LLGS equation. This scheme has a relatively high convergence. The simulation was performed using the Mersenne Twister function built into MATLAB as a random number generator. The parameters were α = 0.01, β = 1.0, H a = 0.2, H k = 0.01, H dz = 1.6, and J = 0.01. In addition, γ = 1.0, and the time step was set to 0.05 to simplify the calculation. In this case, any STNO exhibits in-plane large precession in a steady state.
　まず、ＳＴＮＯ素子対の時間発展を示す。ノイズ強度をδＪ＝０．１Ｊに設定する。このとき、図８（Ａ）に示すように、いずれのＳＴＮＯも定常状態でｉｎ－ｐｌａｎｅ　ｌａｒｇｅ歳差運動となり、同相同期した。対照的に、図８（Ｂ）に示すように、異なるノイズ系列の場合は逆相同期した。 First, the time evolution of the STNO element pair is shown. The noise intensity is set to δJ = 0.1J. At this time, as shown in FIG. 8A, all the STNOs became in-plane large precession in a steady state, and were synchronized in phase. In contrast, as shown in FIG. 8B, in the case of different noise sequences, the anti-phase synchronization was performed.
　図９に、極角θ１とθ２の差の時間発展を示す。図９（Ａ）は同相同期の場合を示し、図９（Ｂ）は逆相同期の場合を示す。過渡状態の後、各ＳＴＮＯはノイズの影響により同期している。これは、過渡状態での同相同期と逆相同期の振舞いはほとんど同じであり、同相同期するか逆相同期するかは同じ確率分布を持つノイズ系列にのみ依存していることに注視すべきである。また、図１０に、極角への位相平面投射図を示す。図１０（Ａ）は、同相同期における過渡状態の投射図、図１０（Ｂ）は、同相同期における安定状態の投射図、図１０（Ｃ）は、逆相同期における過渡状態の投射図、図１０（Ｄ）は、逆相同期における安定状態の投射図である。この結果は確率的同期状態の収束を示している。 FIG. 9 shows the time evolution of the difference between polar angles θ 1 and θ 2 . FIG. 9A shows the case of in-phase synchronization, and FIG. 9B shows the case of anti-phase synchronization. After the transient state, each STNO is synchronized under the influence of noise. Note that the behavior of in-phase and anti-phase synchronization in the transient state is almost the same, and whether in-phase or anti-phase synchronization depends only on noise sequences with the same probability distribution. Should. FIG. 10 shows a phase plane projection diagram for polar angles. 10A is a projection diagram in a transient state in in-phase synchronization, FIG. 10B is a projection diagram in a stable state in in-phase synchronization, and FIG. 10C is a projection diagram in a transient state in anti-phase synchronization. FIG. 10D is a projection diagram of the stable state in the anti-phase synchronization. This result shows the convergence of the stochastic synchronization state.
　以上の結果から、同相同期と逆相同期が起こる確率は同じである。電流を通しての直接的な相互作用を導入することで、同相同期状態はほぼ１００％の確率で起こる（電流相互作用としては、例えば、（参考文献２：Ｄ．Ｌｉ，Ｙ．Ｚｈｏｕ，Ｃ．Ｚｈｏｕ　ａｎｄ　Ｂ．Ｈｕ，Ｐｈｙｓ．Ｒｅｖ．Ｂ，８２，１４０４０７（２０１０）．）、（参考文献３：Ｄ．Ｌｉ，Ｙ．Ｚｈｏｕ，Ｂ．Ｈｕ　ａｎｄ　Ｃ．Ｚｈｏｕ，Ｐｈｙｓ．Ｒｅｖ．Ｂ，８４，１０，１０４４１４（２０１１）．）を参照）。これは、今回の同期機構が、従来の同期機構と協調的かつ相補的に機能し、性能を向上させることを意味する。 From the above results, the probability that in-phase synchronization and anti-phase synchronization will occur is the same. By introducing the direct interaction through the current, the in-phase synchronization state occurs with a probability of almost 100% (for example, (Reference 2: D. Li, Y. Zhou, C. Zhou and B. Hu, Phys. Rev. B, 82, 140407 (2010).) (Reference 3: D. Li, Y. Zhou, B. Hu and C. Zhou, Phys. Rev. B, 84, 10, 104414 (2011).)). This means that the current synchronization mechanism functions cooperatively and complementarily with the conventional synchronization mechanism to improve performance.
　さらに、ＳＴＮＯの歳差運動の状態と同期とクラスタリングの関係を調べた結果、上記実施形態において示したように、ノイズ強度、初期条件に加えて、歳差運動の状態（図４を参照）に依存することが示された。これは、同期状態の確率分布関数が、歳差運動状態を決定するパラメータα、β、Ｊ並びにＨａ、Ｈｋ及びＨｄｚを調整することで、制御できることを示している。 Furthermore, as a result of examining the relationship between the STNO precession state, synchronization, and clustering, as shown in the above embodiment, in addition to the noise intensity and initial conditions, the precession state (see FIG. 4) is obtained. It was shown to depend. This indicates that the probability distribution function of the synchronized state can be controlled by adjusting the parameters α, β, J and H a , H k and H dz that determine the precession state.
　　１　スピン発振装置
　　１１　スピン発振素子
　　１２　スピン発振素子群
　　１３　ノイズ付加手段
　　１４　制御手段 DESCRIPTION OF SYMBOLS 1 Spin oscillation apparatus 11 Spin oscillation element 12 Spin oscillation element group 13 Noise addition means 14 Control means

Claims (12)

  1. 　非磁性体からなる非磁性層が、強磁性体からなる固定層及び自由層の２つの強磁性層で狭持され、前記非磁性層及び前記強磁性層に通電される電流により、スピントルクを作用させて磁化を自励発振する複数のスピン発振素子と、
    　前記複数のスピン発振素子に共通して、当該スピン発振素子の発振周波数よりも高い周波数帯域のノイズを加えるノイズ付加手段と、
    　前記スピン発振素子の前記自由層における磁化の状態及び前記ノイズ付加手段が付加するノイズの状態を制御する制御手段とを備えることを特徴とするスピン発振装置。     A non-magnetic layer made of a non-magnetic material is sandwiched between two ferromagnetic layers, a fixed layer made of a ferromagnetic material and a free layer, and a spin torque is generated by a current passed through the non-magnetic layer and the ferromagnetic layer. A plurality of spin oscillation elements that self-oscillate magnetization by acting;
    A noise adding means for adding noise in a frequency band higher than the oscillation frequency of the spin oscillation element in common to the plurality of spin oscillation elements;
    A spin oscillation device comprising: a control unit that controls a state of magnetization in the free layer of the spin oscillation element and a state of noise added by the noise addition unit.
  2. 　請求項１に記載のスピン発振素子において、
    　前記制御手段が、
    　前記スピン発振素子が振動する際の前記自由層における磁化ベクトルの歳差運動の軌道を、前記固定層における磁化ベクトルに対して面直方向の軸を跨がない軌道に制御することを特徴とするスピン発振装置。     The spin oscillation device according to claim 1,
    The control means is
    The trajectory of the precession of the magnetization vector in the free layer when the spin oscillation element vibrates is controlled to an orbit that does not cross the axis perpendicular to the magnetization vector in the fixed layer. Spin oscillation device.
  3. 　請求項２に記載のスピン発振装置において、
    　前記制御手段が、
    　前記磁化の歳差運動の軌道を、変曲点を有する軌道に制御することを特徴とするスピン発振装置。     The spin oscillation device according to claim 2,
    The control means is
    A spin oscillation device, wherein the orbit of precession of magnetization is controlled to an orbit having an inflection point.
  4. 　請求項３に記載のスピン発振装置において、
    　前記制御手段が、
    　前記変曲点近傍での曲率を基本周波数成分に対する高調波成分の比率に基づいて、制御することを特徴とするスピン発振装置。     The spin oscillation device according to claim 3, wherein
    The control means is
    A spin oscillation device characterized by controlling a curvature in the vicinity of the inflection point based on a ratio of a harmonic component to a fundamental frequency component.
  5. 　請求項３又は４に記載のスピン発振装置において、
    　前記制御手段が、
    　前記変曲点の特徴を、前記スピン発振素子の電流に関するパラメータ及び／又は磁場に関するパラメータにより決定することを特徴とするスピン発振装置。     The spin oscillation device according to claim 3 or 4,
    The control means is
    The spin oscillation device characterized in that the characteristic of the inflection point is determined by a parameter relating to a current of the spin oscillation element and / or a parameter relating to a magnetic field.
  6. 　請求項５に記載のスピン発振装置において、
    　前記制御手段が、
    　前記変曲点近傍での曲率が、前記スピン発振素子が逆相の信号を出力する確率が所定の値以下となるように、前記各パラメータ及びノイズの状態を調整することを特徴とするスピン発振装置。     The spin oscillation device according to claim 5, wherein
    The control means is
    The spin oscillation characterized by adjusting the parameters and the noise state so that the curvature in the vicinity of the inflection point is less than a predetermined value for the probability that the spin oscillation element outputs a signal having a reverse phase. apparatus.
  7. 　請求項６に記載のスピン発振装置において、
    　前記制御手段が、
    　前記パラメータ及びノイズの状態を、位相縮約法から導出される位相応答に基づいて得られる前記パラメータ及びノイズの状態に調整することを特徴とするスピン発振装置。     The spin oscillation device according to claim 6, wherein
    The control means is
    A spin oscillation device characterized by adjusting the parameter and noise state to the parameter and noise state obtained based on a phase response derived from a phase reduction method.
  8. 　請求項１ないし７のいずれかに記載のスピン発振装置において、
    　前記ノイズ付加手段が、前記複数のスピン発振素子を有し、当該複数のスピン発振素子の固有の発振周波数の出力総和を前記ノイズとして付加することを特徴とするスピン発振装置。     The spin oscillation device according to any one of claims 1 to 7,
    The spin oscillation device, wherein the noise adding means includes the plurality of spin oscillation elements, and adds the total output of oscillation frequencies specific to the plurality of spin oscillation elements as the noise.
  9. 　請求項１ないし７のいずれかに記載のスピン発振装置において、
    　前記ノイズ付加手段が、電流変動、磁場変動、熱電流変換素子、光電素子及び／又は圧電素子によりノイズを付加することを特徴とするスピン発振装置。     The spin oscillation device according to any one of claims 1 to 7,
    The spin oscillation device, wherein the noise adding means adds noise by current fluctuation, magnetic field fluctuation, thermal current conversion element, photoelectric element and / or piezoelectric element.
  10. 　請求項１に記載のスピン発振装置において、
    　前記制御手段が、
    　前記スピン発振素子の前記自由層における磁化の初期状態を、前記磁化の磁化ベクトルの方向が揃うように制御することを特徴とするスピン発振装置。     The spin oscillation device according to claim 1,
    The control means is
    A spin oscillation device, wherein an initial state of magnetization in the free layer of the spin oscillation element is controlled so that directions of magnetization vectors of the magnetization are aligned.
  11. 　非磁性体からなる非磁性層が、強磁性体からなる固定層及び自由層の２つの強磁性層で狭持され、前記非磁性層及び前記強磁性層に通電される電流により、スピントルクを作用させて磁化を自励発振する複数のスピン発振素子と、
    　前記複数のスピン発振素子に共通して、当該スピン発振素子の発振周波数よりも高い周波数帯域のノイズを加えるノイズ付加手段とを備え、
    　前記ノイズ付加手段が、前記複数のスピン発振素子を有し、当該複数のスピン発振素子の固有の発振周波数の出力総和を前記ノイズとして付加することを特徴とするスピン発振装置。     A non-magnetic layer made of a non-magnetic material is sandwiched between two ferromagnetic layers, a fixed layer made of a ferromagnetic material and a free layer, and a spin torque is generated by a current passed through the non-magnetic layer and the ferromagnetic layer. A plurality of spin oscillation elements that self-oscillate magnetization by acting;
    In common with the plurality of spin oscillation elements, noise adding means for adding noise in a frequency band higher than the oscillation frequency of the spin oscillation element,
    The spin oscillation device, wherein the noise adding means includes the plurality of spin oscillation elements, and adds the total output of oscillation frequencies specific to the plurality of spin oscillation elements as the noise.
  12. 　非磁性体からなる非磁性層が、強磁性体からなる固定層及び自由層の２つの強磁性層で狭持され、前記非磁性層及び前記強磁性層に通電される電流により、スピントルクを作用させて磁化を自励発振する複数のスピン発振素子と、前記複数のスピン発振素子に共通して、当該スピン発振素子の発振周波数よりも高い周波数帯域のノイズを加えるノイズ付加手段とを備えるスピン発振装置の製造方法であって、
    　前記スピン発振素子の物性に関するパラメータを少なくとも含む特性パラメータ、及び、前記ノイズ付加手段のノイズ特性を、位相縮約法から導出される位相応答に基づいて得られる結果に応じて特定して決定するステップを含むことを特徴とするスピン発振装置の製造方法。     A non-magnetic layer made of a non-magnetic material is sandwiched between two ferromagnetic layers, a fixed layer made of a ferromagnetic material and a free layer, and a spin torque is generated by a current passed through the non-magnetic layer and the ferromagnetic layer. Spin comprising: a plurality of spin oscillation elements that self-oscillate magnetization by acting; and a noise addition unit that adds noise in a frequency band higher than the oscillation frequency of the spin oscillation elements in common to the plurality of spin oscillation elements A method of manufacturing an oscillation device,
    Identifying and determining a characteristic parameter including at least a parameter relating to physical properties of the spin oscillation element and a noise characteristic of the noise adding unit according to a result obtained based on a phase response derived from a phase reduction method A method for manufacturing a spin oscillation device, comprising:
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017065011A1 (en) * 2015-10-13 2017-04-20 ソニー株式会社 Light-emitting device and light-emitting method
JP2017167749A (en) * 2016-03-15 2017-09-21 株式会社東芝 Calculation device and calculation method

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008053915A (en) * 2006-08-23 2008-03-06 Sharp Corp Microwave oscillation element and manufacturing method therefor, and microwave oscillator provided with the microwave oscillation element
WO2009054182A1 (en) * 2007-10-25 2009-04-30 Fuji Electric Holdings Co., Ltd. Spin-valve element and its manufacturing method
JP2009135471A (en) * 2007-10-31 2009-06-18 National Institute Of Advanced Industrial & Technology Microwave oscillation element and detection element
JP2009194070A (en) * 2008-02-13 2009-08-27 Toshiba Corp Magnetic oscillator, magnetic head including the magnetic oscillator, and magnetic recording and reproducing apparatus

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8049567B2 (en) * 2007-11-01 2011-11-01 Johan Persson Circuit for phase locked oscillators
KR20120056019A (en) * 2010-11-24 2012-06-01 삼성전자주식회사 Oscillator and methods of manufacturing and operating the same

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008053915A (en) * 2006-08-23 2008-03-06 Sharp Corp Microwave oscillation element and manufacturing method therefor, and microwave oscillator provided with the microwave oscillation element
WO2009054182A1 (en) * 2007-10-25 2009-04-30 Fuji Electric Holdings Co., Ltd. Spin-valve element and its manufacturing method
JP2009135471A (en) * 2007-10-31 2009-06-18 National Institute Of Advanced Industrial & Technology Microwave oscillation element and detection element
JP2009194070A (en) * 2008-02-13 2009-08-27 Toshiba Corp Magnetic oscillator, magnetic head including the magnetic oscillator, and magnetic recording and reproducing apparatus

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
KAZUYUKI YOSHIMURA: "Phase Reduction of Limit Cycle Oscillators Driven by Noise", IEICE TECHNICAL REPORT, vol. 110, no. 83, 11 June 2010 (2010-06-11), pages 141 - 145 *
YUYA NAKAO: "Phase Reduction Theory of Nonlinear Oscillators and its Applications", SYSTEM SEIGYO JOHO GAKKAISHI SYSTEM/SEIGYO/JOHO, vol. 53, no. 8, 15 August 2009 (2009-08-15), pages 12 - 18 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017065011A1 (en) * 2015-10-13 2017-04-20 ソニー株式会社 Light-emitting device and light-emitting method
US10295846B2 (en) 2015-10-13 2019-05-21 Sony Semiconductor Solutions Corporation Light emitting device and light emitting method
JP2017167749A (en) * 2016-03-15 2017-09-21 株式会社東芝 Calculation device and calculation method

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