JP2013134995A - Spin polarization measuring method and measuring meter, logical operation gate using the same and signal encryption decryption method - Google Patents

Spin polarization measuring method and measuring meter, logical operation gate using the same and signal encryption decryption method Download PDF

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JP2013134995A
JP2013134995A JP2011282394A JP2011282394A JP2013134995A JP 2013134995 A JP2013134995 A JP 2013134995A JP 2011282394 A JP2011282394 A JP 2011282394A JP 2011282394 A JP2011282394 A JP 2011282394A JP 2013134995 A JP2013134995 A JP 2013134995A
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Masamichi Sakai
政道 酒井
Shigehiko Hasegawa
繁彦 長谷川
Akira Kitajima
彰 北島
Akihiro Oshima
明博 大島
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Saitama University NUC
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Abstract

PROBLEM TO BE SOLVED: To provide spin polarization measuring method and meter capable of measuring spin polarization without being restricted by a measured material or the measuring temperature.SOLUTION: A longitudinal voltage Vand a lateral voltage Vparallel with and perpendicular to a spin polarization current Iinjected from a measured material 2 into a nonmagnetic conductor 3 are measured and divided by a longitudinal current Ithus obtaining a longitudinal resistance Rand a lateral resistance R. The longitudinal and lateral resistivity ratio ρ/ρis obtained by multiplying a value, obtained by dividing the lateral resistance Rby the longitudinal resistance R, by the width of the nonmagnetic conductor 3 and then dividing the product by the length L of the nonmagnetic conductor 3. Since the longitudinal and lateral resistivity ratio ρ/ρand the spin polarization Puse the product μS of carrier mobility μ and the intensity S of spin orbit interaction as a proportionality coefficient, relative value of spin polarization Pcan be evaluated from the longitudinal and lateral resistivity ratio ρ/ρ. Absolute value of spin polarization Pcan be evaluated using the proportionality coefficient μS obtained by measuring each longitudinal resistivity ρwhen injecting currents having spin polarization Pof 0% and 100% into the nonmagnetic conductor 3.

Description

本発明は、被測定材料におけるキャリアのスピン偏極度を測定するスピン偏極度測定方法、及びスピン偏極度測定メータ、並びにこのスピン偏極度測定メータを用いた論理演算ゲート及び信号暗号化復号化方法に関するものである。   The present invention relates to a spin polarization measurement method for measuring the spin polarization of carriers in a material to be measured, a spin polarization measurement meter, a logic operation gate using the spin polarization measurement meter, and a signal encryption / decryption method. Is.

従来、固体中におけるキャリアのスピン偏極度測定方法には、主に、特許文献１及び非特許文献１に開示されたスピン偏極トンネリング効果を用いる方法と、非特許文献２に開示されたアンドレーフ反射を利用する方法の２種類がある。   Conventionally, methods for measuring the spin polarization of carriers in a solid mainly include a method using a spin-polarized tunneling effect disclosed in Patent Document 1 and Non-Patent Document 1, and an Andreff reflection disclosed in Non-Patent Document 2. There are two types of methods that use.

前者のスピン偏極トンネリング効果を用いる方法では、絶縁層を介して強磁性層を積層した、第１の強磁性層／絶縁層／第２の強磁性層という３層構造の磁気抵抗効果素子を使う。そして、第１及び第２の強磁性層間に現れるスピン偏極トンネリング効果を利用する。スピン偏極トンネリング効果における磁気抵抗変化率は、第１の強磁性層と第２の強磁性層の伝導電子スピン偏極度をそれぞれＰ１、Ｐ２とすると、大まかに両者の積の２倍、すなわち２Ｐ１×Ｐ２と表される。従って、スピン偏極度Ｐ１が明確である第１の強磁性層を使用し、磁気抵抗変化率を測定することにより、第２の強磁性層のスピン偏極度Ｐ２を求めることが出来る。この方法は、実際の磁気抵抗効果素子の製造に必要な情報が直接得られるという利点を有している。   In the former method using the spin-polarized tunneling effect, a magnetoresistive effect element having a three-layer structure of a first ferromagnetic layer / insulating layer / second ferromagnetic layer in which a ferromagnetic layer is stacked via an insulating layer is formed. use. Then, the spin-polarized tunneling effect that appears between the first and second ferromagnetic layers is used. The rate of change in magnetoresistance in the spin-polarized tunneling effect is roughly twice the product of the two when the conduction electron spin polarization degrees of the first ferromagnetic layer and the second ferromagnetic layer are P1 and P2, respectively, that is, 2P1. XP2. Therefore, the spin polarization degree P2 of the second ferromagnetic layer can be obtained by using the first ferromagnetic layer with a clear spin polarization degree P1 and measuring the magnetoresistance change rate. This method has an advantage that information necessary for manufacturing an actual magnetoresistive element can be directly obtained.

また、後者のアンドレーフ反射を利用する方法では、被測定材料に超伝導体を接合しておく。そして、被測定材料から超伝導体への入射電子がクーパー対を生成する際に、正孔が被測定材料へ反射されるという現象を利用して、スピン偏極度を測定する。   Further, in the latter method using Andreev reflection, a superconductor is bonded to the material to be measured. Then, the spin polarization degree is measured by utilizing a phenomenon that holes are reflected to the material to be measured when electrons incident on the superconductor from the material to be measured generate a Cooper pair.

特開平１１−６４４７６号公報Japanese Patent Laid-Open No. 11-64476

R.Meservey and O.M.Tedrow, Phys. Rep. 238巻(1994年), 173頁R. Meservey and O.M.Tedrow, Phys. Rep. 238 (1994), 173 M.J.M. de Jong and C.W.J.Beenakker, Phys. Rev. Lett. 74巻 (1995年), 1657頁M.J.M.de Jong and C.W.J.Beenakker, Phys. Rev. Lett. 74 (1995), 1657

しかしながら、上記従来のスピン偏極トンネリング効果を用いて第２の強磁性層のスピン偏極度Ｐ２を測定するには、予め第１の強磁性層のスピン偏極度Ｐ１を決定しておく必要がある。さらに、被測定材料は強磁性体に限られる。また、キャリアは２種類の磁性層を通過するので、強磁性層の局在スピンとの相互作用によってキャリヤのスピン状態が変化し、ひいては、キャリアのスピン偏極度はこの測定によって変化してしまう。このように、従来のスピン偏極トンネリング効果を用いた方法では、磁気抵抗変化の測定中にキャリアのスピン偏極度の値が変化しないことが保証できない。さらに、測定の原理上、大がかりな走査型トンネル電子顕微鏡（ＳＴＭ）技術を必要とするため、スピン偏極度の測定を簡便に行ってその測定結果を新たな回路素子へ応用することは困難である。   However, in order to measure the spin polarization degree P2 of the second ferromagnetic layer using the conventional spin polarization tunneling effect, it is necessary to determine the spin polarization degree P1 of the first ferromagnetic layer in advance. . Furthermore, the material to be measured is limited to a ferromagnetic material. Further, since the carriers pass through the two types of magnetic layers, the spin state of the carriers changes due to the interaction with the localized spins of the ferromagnetic layer, and consequently the spin polarization of the carriers changes due to this measurement. Thus, the conventional method using the spin-polarized tunneling effect cannot guarantee that the value of the carrier spin-polarization does not change during the measurement of the magnetoresistance change. Furthermore, since the principle of measurement requires a large-scale scanning tunneling electron microscope (STM) technique, it is difficult to simply measure the degree of spin polarization and apply the measurement result to a new circuit element. .

また、上記従来のアンドレーフ反射を利用してスピン偏極度を測定するには、被測定材料全体を超伝導状態に達するまで冷却する必要がある。さらに、被測定材料のフェルミ準位が電子に占有されている必要があるため、被測定材料は金属に限られる。   Further, in order to measure the spin polarization using the conventional Andreev reflection, it is necessary to cool the entire material to be measured until it reaches a superconducting state. Furthermore, since the Fermi level of the material to be measured needs to be occupied by electrons, the material to be measured is limited to metal.

このように従来のスピン偏極度を測定する方法は、被測定材料の材質及び測定温度に制約があり、例えば、半導体のスピン偏極度を室温下で測定するのは大変困難である。   As described above, the conventional method for measuring the spin polarization has restrictions on the material to be measured and the measurement temperature. For example, it is very difficult to measure the spin polarization of a semiconductor at room temperature.

本発明はこのような課題を解決するためになされたもので、導電性を有する被測定材料に接合された非磁性導体に前記被測定材料から注入されたスピン偏極電流の進行方向に沿う縦方向の縦抵抗を測定し、電流進行方向に直交する横方向における非磁性導体の横抵抗を測定し、測定した縦抵抗及び横抵抗から非磁性導体の横抵抗率の縦抵抗率に対する縦横抵抗率比を求め、縦横抵抗率比と非磁性導体におけるキャリアのスピン偏極度とが、非磁性導体におけるキャリアの移動度とスピン軌道相互作用の強さとの積を比例係数とする比例関係にあることに基づいて、縦横抵抗率比から被測定材料のスピン偏極度の相対値を評価するスピン偏極度測定方法を構成した。   The present invention has been made in order to solve such a problem, and a longitudinal direction along the traveling direction of the spin-polarized current injected from the measured material into the nonmagnetic conductor bonded to the measured material having conductivity. Measure the longitudinal resistance in the direction, measure the transverse resistance of the nonmagnetic conductor in the transverse direction perpendicular to the direction of current travel, and measure the longitudinal resistance from the measured longitudinal resistance and lateral resistance to the longitudinal resistivity of the nonmagnetic conductor. The ratio of longitudinal and lateral resistivity and the spin polarization of the carrier in the nonmagnetic conductor are in a proportional relationship with the product of the mobility of the carrier in the nonmagnetic conductor and the strength of the spin orbit interaction as a proportional coefficient. Based on this, a spin polarization measuring method for evaluating the relative value of the spin polarization of the material to be measured from the aspect ratio of the longitudinal and lateral directions was constructed.

本構成によれば、導電性を有する被測定材料に接合された非磁性導体を流れるスピン偏極電流の進行方向に沿う縦方向の縦抵抗、及びこれに直交する横方向の横抵抗を測定し、測定した縦抵抗及び横抵抗から非磁性導体の縦横抵抗率比を求めることで、縦横抵抗率比と非磁性導体におけるキャリアのスピン偏極度とが比例関係にあることに基づいて、縦横抵抗率比から被測定材料のスピン偏極度の相対値を評価することが出来る。   According to this configuration, the longitudinal longitudinal resistance along the traveling direction of the spin-polarized current flowing through the nonmagnetic conductor joined to the conductive material to be measured, and the transverse resistance perpendicular to the longitudinal direction are measured. Based on the fact that the longitudinal and lateral resistivity ratio of the nonmagnetic conductor is obtained from the measured longitudinal resistance and lateral resistance, the longitudinal and lateral resistivity ratio is proportional to the spin polarization of the carrier in the nonmagnetic conductor. The relative value of the degree of spin polarization of the material to be measured can be evaluated from the ratio.

このため、従来のスピン偏極トンネリング効果を用いたスピン偏極度測定方法のように被測定材料が強磁性体に限られることはなく、また、従来のアンドレーフ反射を利用したスピン偏極度測定方法のように被測定材料が金属に限られることはなく、被測定材料は導電性を持ちさえすれば、非磁性導体の横抵抗と縦抵抗を測定するだけで、金属か半導体かに依らず、被測定材料におけるキャリアのスピン偏極度を評価することが可能になる。しかも、従来のアンドレーフ反射を利用したスピン偏極度測定方法のように、被測定材料全体を超伝導状態に達するまで冷却する必要もなく、任意の測定周囲温度で、キャリアのスピン偏極度を評価することが可能になる。また、キャリアが２種類の強磁性層を通過する従来のスピン偏極トンネリング効果を用いた測定方法とは異なり、測定中にキャリアのスピン偏極度の値が変化しないことが保証される。さらに、大がかりなＳＴＭ技術を必要としないため、スピン偏極度の測定を簡便に行ってその測定結果を論理ゲートのような新たな回路素子へ応用することが可能になる。   Therefore, the material to be measured is not limited to a ferromagnetic material as in the conventional spin polarization measurement method using the spin polarization tunneling effect, and the conventional spin polarization measurement method using Andreff reflection is used. Thus, the material to be measured is not limited to metal, and as long as the material to be measured has conductivity, it is only necessary to measure the lateral resistance and longitudinal resistance of the nonmagnetic conductor, regardless of whether it is metal or semiconductor. It becomes possible to evaluate the spin polarization of the carrier in the measurement material. Moreover, unlike the conventional spin polarization measurement method using Andreff reflection, it is not necessary to cool the entire material to be measured until it reaches the superconducting state, and the carrier spin polarization is evaluated at any measurement ambient temperature. It becomes possible. Further, unlike the measurement method using the conventional spin polarization tunneling effect in which carriers pass through two types of ferromagnetic layers, it is guaranteed that the value of the carrier spin polarization does not change during measurement. Furthermore, since a large-scale STM technique is not required, it is possible to easily measure the spin polarization and apply the measurement result to a new circuit element such as a logic gate.

また、本発明は、スピン偏極度が０％のときの縦抵抗率の、スピン偏極度が１００％のときの縦抵抗率に対する比から１を減算した減算値で、或るスピン偏極度における縦横抵抗率比の二乗値を割った値がそのスピン偏極度の二乗値に等しい関係に基づいて、被測定材料のスピン偏極度の絶対値を評価することを特徴とする。   Further, the present invention is a subtracted value obtained by subtracting 1 from the ratio of the longitudinal resistivity when the spin polarization is 0% to the longitudinal resistivity when the spin polarization is 100%. The absolute value of the spin polarization degree of the material to be measured is evaluated based on a relationship in which the value obtained by dividing the square value of the resistivity ratio is equal to the square value of the spin polarization degree.

本構成によれば、非磁性導体の縦横抵抗率比に加えて、スピン偏極度が０％および１００％の電流を非磁性導体に注入したときの各縦抵抗率を測定することで、これら各特性値の予め導かれている上記関係に基づいて、被測定材料のスピン偏極度の絶対値を評価することが出来る。このため、従来のスピン偏極トンネリング効果を用いたスピン偏極度測定方法のように、２種類の強磁性層のうちの一方の強磁性層のスピン偏極度を予め決定しておく必要もなく、簡易にスピン偏極度の絶対値を評価することが出来る。   According to this configuration, in addition to the longitudinal and lateral resistivity ratio of the nonmagnetic conductor, each longitudinal resistivity when the current having a spin polarization of 0% and 100% is injected into the nonmagnetic conductor is measured. The absolute value of the spin polarization degree of the material to be measured can be evaluated based on the above-described relationship in which the characteristic values are derived in advance. Therefore, unlike the conventional spin polarization measurement method using the spin polarization tunneling effect, it is not necessary to previously determine the spin polarization of one of the two ferromagnetic layers, The absolute value of spin polarization can be easily evaluated.

また、本発明は、被測定材料に非磁性導体が接合されて構成される素子の両端に電圧を印加して被測定材料から非磁性導体にスピン偏極電流を注入し、非磁性導体におけるスピン偏極電流の進行方向に平行な縦方向電圧、及びスピン偏極電流の進行方向に垂直な横方向電圧を測定し、縦方向電圧をスピン偏極電流の電流値で割った値を縦抵抗、横方向電圧をスピン偏極電流の電流値で割った値を横抵抗とすることを特徴とする。   The present invention also applies a voltage to both ends of an element formed by bonding a nonmagnetic conductor to a material to be measured to inject a spin-polarized current from the material to be measured into the nonmagnetic conductor, Measure the longitudinal voltage parallel to the direction of travel of the polarized current and the lateral voltage perpendicular to the direction of travel of the spin-polarized current, and the value obtained by dividing the longitudinal voltage by the current value of the spin-polarized current is the longitudinal resistance. A value obtained by dividing the lateral voltage by the current value of the spin-polarized current is defined as a lateral resistance.

本構成によれば、被測定材料から非磁性導体に注入したスピン偏極電流の進行方向に対して平行及び垂直な縦方向電圧及び横方向電圧を測定し、測定した各電圧値を注入したスピン偏極電流の電流値で割ることで、縦抵抗及び横抵抗の値を求めることが出来る。このため、キャリアの走行状態に摂動を加えずにスピン偏極度の評価を行うことが可能になる。   According to this configuration, the longitudinal voltage and the lateral voltage that are parallel and perpendicular to the traveling direction of the spin-polarized current injected from the material to be measured to the nonmagnetic conductor are measured, and the measured voltage values are injected into the spin. By dividing by the current value of the polarized current, the values of the longitudinal resistance and the lateral resistance can be obtained. For this reason, it is possible to evaluate the spin polarization without adding perturbation to the traveling state of the carrier.

また、本発明は、導電性を有する被測定材料に非磁性導体が接合されたメータ本体と、メータ本体の両端に電圧を印加して被測定材料から非磁性導体に注入されたスピン偏極電流の進行方向に平行な縦方向電圧を測定する第１の電圧測定手段と、スピン偏極電流の進行方向に垂直な横方向電圧を測定する第２の電圧測定手段とから、スピン偏極度測定メータを構成した。   The present invention also provides a meter body in which a nonmagnetic conductor is bonded to a material to be measured having conductivity, and a spin-polarized current injected from the material to be measured into the nonmagnetic conductor by applying a voltage to both ends of the meter body. A spin polarization degree measuring meter comprising: a first voltage measuring means for measuring a longitudinal voltage parallel to the traveling direction of the first and a second voltage measuring means for measuring a lateral voltage perpendicular to the traveling direction of the spin polarized current; Configured.

本構成によれば、メータ本体の両端に電圧を印加してメータ本体における被測定材料から非磁性導体にスピン偏極電流を注入し、注入したスピン偏極電流の進行方向に平行及び垂直な縦方向及び横方向電圧を第１及び第２の電圧測定手段で測定することで、縦抵抗及び横抵抗の値を求めることが出来る。このため、キャリアの走行状態に摂動を加えずにスピン偏極度の評価を簡便に行うことが可能なスピン偏極度測定メータが提供される。   According to this configuration, a voltage is applied to both ends of the meter body to inject a spin-polarized current from the material to be measured in the meter body into the nonmagnetic conductor, and vertical and parallel to the traveling direction of the injected spin-polarized current. By measuring the directional and lateral voltages with the first and second voltage measuring means, the values of the longitudinal resistance and the lateral resistance can be obtained. Therefore, a spin polarization measurement meter is provided that can easily evaluate the spin polarization without adding perturbation to the carrier running state.

また、本発明は、
導電性を有する第１の導電材料に第１の非磁性導体が接合された第１のメータ本体、第１のメータ本体の両端に電圧を印加して第１の導電材料から第１の非磁性導体に注入された第１のスピン偏極電流の進行方向に平行な縦方向電圧を測定する第１の電圧測定手段、及び、第１のスピン偏極電流の進行方向に垂直な横方向電圧を測定する第２の電圧測定手段から構成される第１のスピン偏極度測定メータと、
導電性を有する第２の導電材料に第２の非磁性導体が接合された第２のメータ本体、第２のメータ本体の両端に電圧を印加して第２の導電材料から第２の非磁性導体に注入された第２のスピン偏極電流の進行方向に平行な縦方向電圧を測定する第３の電圧測定手段、及び、第２のスピン偏極電流の進行方向に垂直な横方向電圧を測定する第４の電圧測定手段から構成される第２のスピン偏極度測定メータと、
第３の非磁性導体からなる第３のメータ本体、第１の非磁性導体及び第２の非磁性導体から第３の非磁性導体に流入する第１のスピン偏極電流及び第２のスピン偏極電流が合成して形成される第３のスピン偏極電流の進行方向に平行な縦方向電圧を測定する第５の電圧測定手段、及び、第３のスピン偏極電流の進行方向に垂直な横方向電圧を測定する第６の電圧測定手段から構成される第３のスピン偏極度測定メータと
を備えて構成され、
第１のスピン偏極電流のキャリアのスピン偏極度及び第２のスピン偏極電流のキャリアのスピン偏極度を入力値、第３のスピン偏極電流のキャリアのスピン偏極度を出力値とする論理演算ゲートを構成した。 The present invention also provides:
A first meter main body in which a first nonmagnetic conductor is joined to a first conductive material having conductivity, and a voltage is applied to both ends of the first meter main body to apply a first nonmagnetic from the first conductive material. First voltage measuring means for measuring a longitudinal voltage parallel to the traveling direction of the first spin-polarized current injected into the conductor, and a lateral voltage perpendicular to the traveling direction of the first spin-polarized current. A first spin polarization measuring meter comprising second voltage measuring means for measuring;
A second meter main body in which a second nonmagnetic conductor is joined to a second conductive material having conductivity, and a voltage is applied to both ends of the second meter main body to apply a second nonmagnetic from the second conductive material. Third voltage measuring means for measuring a longitudinal voltage parallel to the traveling direction of the second spin-polarized current injected into the conductor, and a lateral voltage perpendicular to the traveling direction of the second spin-polarized current A second spin polarization measuring meter comprising fourth voltage measuring means for measuring;
A first spin-polarized current and a second spin-polarized current flowing from the third non-magnetic conductor into the third non-magnetic conductor, the first non-magnetic conductor, and the second non-magnetic conductor. Fifth voltage measuring means for measuring a longitudinal voltage parallel to the traveling direction of the third spin-polarized current formed by combining the polar currents, and perpendicular to the traveling direction of the third spin-polarized current A third spin polarization measuring meter comprising a sixth voltage measuring means for measuring a lateral voltage,
Logic having the spin polarization of the carrier of the first spin-polarized current and the spin polarization of the carrier of the second spin-polarized current as input values and the spin polarization of the carriers of the third spin-polarized current as output values Arithmetic gate was constructed.

本構成によれば、第１のメータ本体及び第２のメータ本体にそれぞれスピン偏極度が１００％の第１のスピン偏極電流及び第２のスピン偏極電流を注入すると、第３のメータ本体にはスピン偏極度が１００％の第３のスピン偏極電流が流れる。また、第１のメータ本体及び第２のメータ本体にそれぞれスピン偏極度が１００％の第１のスピン偏極電流及びスピン偏極度が−１００％の第２のスピン偏極電流を注入すると、第３のメータ本体にはスピン偏極度が０％の第３のスピン偏極電流が流れる。また、第１のメータ本体及び第２のメータ本体にそれぞれスピン偏極度が−１００％の第１のスピン偏極電流及びスピン偏極度が１００％の第２のスピン偏極電流を注入すると、第３のメータ本体にはスピン偏極度が０％の第３のスピン偏極電流が流れる。また、第１のメータ本体及び第２のメータ本体にそれぞれスピン偏極度が−１００％の第１のスピン偏極電流及び第２のスピン偏極電流を注入すると、第３のメータ本体にはスピン偏極度が−１００％の第３のスピン偏極電流が流れる。   According to this configuration, when a first spin-polarized current and a second spin-polarized current having a spin polarization degree of 100% are injected into the first meter body and the second meter body, respectively, the third meter body Flows a third spin-polarized current having a spin polarization of 100%. Further, when a first spin polarization current having a spin polarization of 100% and a second spin polarization current having a spin polarization of −100% are injected into the first meter body and the second meter body, respectively, A third spin-polarized current having a spin polarization degree of 0% flows through the meter body 3. Further, when a first spin-polarized current having a spin polarization degree of −100% and a second spin-polarized current having a spin polarization degree of 100% are injected into the first meter body and the second meter body, respectively, A third spin-polarized current having a spin polarization degree of 0% flows through the meter body 3. Further, when a first spin-polarized current and a second spin-polarized current having a spin polarization degree of −100% are injected into the first meter body and the second meter body, respectively, the third meter body is spun. A third spin-polarized current having a polarization degree of −100% flows.

このため、第１のスピン偏極電流のキャリアのスピン偏極度及び第２のスピン偏極電流のキャリアのスピン偏極度を入力値、第３のスピン偏極電流のキャリアのスピン偏極度を出力値とすると、出力値及び一方の入力値が分かると、他方の入力値が一義的に推測される。ここで、各入力値及び出力値は、第１〜第３の各メータ本体を流れる第１〜第３の各スピン偏極電流の進行方向に平行な縦方向電圧及びこれに垂直な横方向電圧を第１〜第６の各電圧測定手段で測定し、縦抵抗及び横抵抗を求めてスピン偏極度を算出することで、得られる。出力値及び一方の入力値から他方の入力値が一義的に推測されるこのような論理関係は、排他的論理和の論理演算ゲートにおける入力値及び出力値の論理関係に類似する。従って、本構成により擬似排他的な論理和を演算する擬似排他的論理演算ゲートが提供される。   Therefore, the spin polarization degree of the carrier of the first spin polarization current and the spin polarization degree of the carrier of the second spin polarization current are input values, and the spin polarization degree of the carriers of the third spin polarization current is an output value. Then, when the output value and one input value are known, the other input value is uniquely estimated. Here, the input value and the output value are the vertical voltage parallel to the traveling direction of the first to third spin-polarized currents flowing through the first to third meter bodies, and the horizontal voltage perpendicular thereto. Is measured by each of the first to sixth voltage measuring means, the longitudinal resistance and the lateral resistance are obtained, and the spin polarization is calculated. Such a logical relationship in which the other input value is uniquely estimated from the output value and one input value is similar to the logical relationship between the input value and the output value in the logical operation gate of exclusive OR. Therefore, this configuration provides a pseudo-exclusive logic operation gate that calculates a pseudo-exclusive OR.

また、本発明は、第１のメータ本体及び第２のメータ本体の一方に送信信号列、他方に乱数列を入力して第３のメータ本体から出力される信号列を暗号列として送信し、上記の論理演算ゲートの演算論理に基づいて乱数列と受信した暗号列とから送信信号列を復号する、上記の論理演算ゲートを用いた信号暗号化及び復号化方法を構成した。   In the present invention, a transmission signal string is input to one of the first meter body and the second meter body, a random number string is input to the other, and a signal string output from the third meter body is transmitted as an encryption string. A signal encryption and decryption method using the above-described logic operation gate is configured to decrypt the transmission signal sequence from the random number sequence and the received encrypted sequence based on the operation logic of the above-described logic operation gate.

本構成によれば、第１のメータ本体に入力される送信信号列と第２のメータ本体に入力される乱数列とは、上記の論理演算ゲートによって上述した擬似排他的な論理和がとられ、その論理演算結果が暗号列として第３のメータ本体から出力され、送信される。上記の論理演算ゲートは、出力値である暗号列及び一方の入力値である乱数列から他方の入力値である入力信号列が一義的に推測されるので、受信側では、乱数列と受信した暗号列とから、上記の論理演算ゲートの演算論理に基づいて、送信した信号列を復号化することが出来る。   According to this configuration, the transmission signal sequence input to the first meter body and the random number sequence input to the second meter body are subjected to the above-described pseudo-exclusive OR by the logic operation gate. The logical operation result is output from the third meter body as an encrypted string and transmitted. In the above logical operation gate, since the input signal sequence that is the other input value is uniquely estimated from the encrypted sequence that is the output value and the random number sequence that is the one input value, the receiving side has received the random number sequence and From the cipher string, the transmitted signal string can be decrypted based on the arithmetic logic of the logical operation gate.

このため、上記の論理演算ゲートを用いることで、送信信号列を暗号列に暗号化することが出来、暗号列を送信信号列に復号化することが出来る新たな信号暗号化及び復号化方法が提供される。   For this reason, a new signal encryption and decryption method capable of encrypting a transmission signal string into an encrypted string and decrypting an encrypted string into a transmission signal string by using the logic operation gate described above is provided. Provided.

本発明によれば、上記のように、被測定材料の材質及び測定温度に制約を受けること無く、被測定材料におけるキャリアのスピン偏極度を簡便に測定することが出来るスピン偏極度測定方法、及びスピン偏極度測定メータが提供される。このため、例えば、半導体のスピン偏極度を室温下で測定することが可能になる。また、このスピン偏極度測定メータを用いることで、擬似排他的な論理和を演算する論理演算ゲートが提供され、さらに、この論理演算ゲートを用いることで、新たな信号暗号化及び復号化方法が提供される。   According to the present invention, as described above, the spin polarization measurement method that can easily measure the spin polarization of carriers in the material to be measured without being restricted by the material and measurement temperature of the material to be measured, and A spin polarization measurement meter is provided. For this reason, for example, it becomes possible to measure the spin polarization of a semiconductor at room temperature. Further, by using this spin polarization measurement meter, a logical operation gate for calculating a quasi-exclusive OR is provided. Further, by using this logical operation gate, a new signal encryption and decryption method is provided. Provided.

（ａ）は、伝導電子のスピン偏極度Ｐｓが１００％のときにおける既知の異常ホール効果、（ｂ）は、スピン偏極度Ｐｓが０％のときにおける既知の異常ホール効果（スピンホール効果）を説明するための図である。(A) is a known anomalous Hall effect when the spin polarization degree P s of conduction electrons is 100%, and (b) is a known anomalous Hall effect (spin Hall effect when the spin polarization degree P s is 0%). FIG. 本発明の一実施の形態によるスピン偏極度測定方法の原理に用いられている、スピン偏極度測定メータのチャネル領域における縦抵抗ρｘｘと横抵抗ρｙｘがともにキャリアのスピン偏極度Ｐｓに依存する関係を説明するための表図である。The longitudinal resistance ρ xx and the lateral resistance ρ yx in the channel region of the spin polarization measurement meter used in the principle of the spin polarization measurement method according to the embodiment of the present invention both depend on the carrier spin polarization P s . It is a table for demonstrating the relationship to do. 本発明の一実施の形態によるスピン偏極度測定メータの概略構成を示す斜視図である。It is a perspective view which shows schematic structure of the spin-polarization degree measuring meter by one embodiment of this invention. （ａ）は、図３に示すスピン偏極度測定メータの較正に用いられる較正器の概略構成を示す斜視図、（ｂ）はこの較正器で得られた較正グラフである。(A) is a perspective view which shows schematic structure of the calibrator used for calibration of the spin polarization degree meter shown in FIG. 3, (b) is a calibration graph obtained by this calibrator. 図３に示すスピン偏極度測定メータを用いた本発明の一実施の形態による演算論理ゲートの概略構成を示す斜視図である。It is a perspective view which shows schematic structure of the arithmetic logic gate by one Embodiment of this invention using the spin polarization degree measurement meter shown in FIG. （ａ）は図５に示す擬似ＸＯＲ演算論理ゲートの真理値表、（ｂ）は一般的なＸＯＲ演算論理ゲートの真理値表を示す表図である。(A) is a truth table of the pseudo XOR operation logic gate shown in FIG. 5, and (b) is a table showing a truth table of a general XOR operation logic gate. 一般的なＸＯＲ演算論理ゲートをバイポーラ・トランジスタで構成した一例の回路図である。It is a circuit diagram of an example in which a general XOR operation logic gate is composed of bipolar transistors. 図５に示す演算論理ゲートを用いた本発明の一実施の形態による信号暗号化及び復号化方法における送信側及び受信側の各信号列の関係を示す図である。It is a figure which shows the relationship between each signal sequence of the transmission side in the signal encryption and decoding method by one Embodiment of this invention using the arithmetic logic gate shown in FIG. 5, and a receiving side.

次に、被測定材料におけるキャリアのスピン偏極度を測定する本発明によるスピン偏極度測定方法の一実施の形態について説明する。   Next, an embodiment of a spin polarization measurement method according to the present invention for measuring the spin polarization of carriers in a material to be measured will be described.

本実施の形態によるスピン偏極度測定方法は、次の（１）式に表される原理に基づいている。

Figure 2013134995
The spin polarization measurement method according to the present embodiment is based on the principle expressed by the following equation (1).
Figure 2013134995

ここで、ρｘｘは、導電性を有する被測定材料に接合された非磁性チャネル領域に注入されたスピン偏極電流進行方向に沿う縦方向におけるチャネル領域の縦抵抗率、ρｙｘは、電流進行方向に直交する横方向におけるチャネル領域の横抵抗率である。また、μはキャリアである伝導電子の移動度であり、電子の電荷量及び質量をそれぞれｑ及びｍ、電子の散乱緩和時間をτとすると、μ＝ｑτ／ｍと表される。また、Ｓはスピン軌道相互作用の強さ、Ｐｓはスピン偏極度である。スピン偏極度Ｐｓは、次の（２）式によって定義される。

Figure 2013134995
Here, ρ xx is the longitudinal resistivity of the channel region in the longitudinal direction along the direction of travel of the spin-polarized current injected into the nonmagnetic channel region bonded to the conductive material to be measured, and ρ yx is the current progression. It is the lateral resistivity of the channel region in the lateral direction orthogonal to the direction. Further, μ is the mobility of conduction electrons as carriers, and is expressed as μ = qτ / m, where q and m are the charge amount and mass of the electron, and τ is the electron scattering relaxation time. Further, S is strength of the spin-orbit interaction, P s is the extreme spin polarized. The spin polarization P s is defined by the following equation (2).
Figure 2013134995

ここで、ｎαはチャネル領域におけるスピンアップ電子の電子密度、ｎβはスピンダウン電子の電子密度である。 Here, n α is the electron density of spin-up electrons in the channel region, and n β is the electron density of spin-down electrons.

上記の（１）式は、横抵抗率ρｙｘの縦抵抗率ρｘｘに対する縦横抵抗率比ρｙｘ／ρｘｘとチャネル領域におけるキャリアのスピン偏極度Ｐｓとが、チャネル領域におけるキャリアの移動度μとスピン軌道相互作用の強さＳとの積μＳを比例係数とする比例関係にあることを表している。ここで、積μＳはスピン偏極度Ｐｓの検出感度を与える。 The above formula (1), the spin polarization P s of the carriers in the aspect resistivity ratio ρ yx / ρ xx and the channel region with respect to the vertical resistivity [rho xx lateral resistivity [rho yx is, the mobility of carriers in the channel region It represents that the product has a proportional relationship with the product μS of μ and the strength S of the spin orbit interaction S as a proportional coefficient. Here, the product μS gives detection sensitivity of the spin polarization P s.

本実施の形態によるスピン偏極度測定方法では、上記の縦抵抗率ρｘｘ及び横抵抗率ρｙｘを測定する。そして、測定した横抵抗率ρｙｘの縦抵抗率ρｘｘに対する縦横抵抗率比ρｙｘ／ρｘｘとスピン偏極度Ｐｓとが（１）式で表される比例関係にある上述の原理に基づいて、被測定材料におけるスピン偏極度Ｐｓの相対値を評価する。移動度μとスピン軌道相互作用の強さＳとはスピン偏極度Ｐｓに依存しない量であるため、このようなスピン偏極度Ｐｓの相対値測定が可能になっている。 In the spin polarization measuring method according to the present embodiment, the longitudinal resistivity ρ xx and the lateral resistivity ρ yx are measured. Then, based on the above-described principle, the ratio of the longitudinal and lateral resistivity ρ yx / ρ xx to the longitudinal resistivity ρ xx of the measured lateral resistivity ρ yx and the spin polarization P s are in a proportional relationship represented by the equation (1). Thus, the relative value of the spin polarization degree P s in the measured material is evaluated. Since the mobility μ is the magnitude S of the spin-orbit interaction is an amount that is independent of the spin polarization P s, it has become capable of relative measurement of the spin polarization P s.

ここで（１）式が成立する理由を直感的方法にもとづいて説明する。図１（ａ）に示すように、ｚ方向のスピン磁気モーメントｍを有する伝導電子１のスピン偏極度Ｐｓを１００％にして、つまり、全ての伝導電子１のスピンをアップにして、チャネル領域δにｘ方向にバイアス電流Ｉを流すとき、伝導電子１の軌道はスピン軌道相互作用による力ｆＳＯＩよって同一の−ｙ方向に反れる。このため、チャネル領域δの内部に電荷の偏りが生じ、異常ホール効果によってホール電場ＥＨが発生して、伝導電子１にはホール電気力ｆＨａｌｌがｙ方向に作用する。定常状態では、伝導電子１に作用するホール電気力ｆＨａｌｌとスピン軌道相互作用力ｆＳＯＩとが釣り合う。従って、伝導電子１にスピン軌道相互作用が作用しても、伝導電子１の直進性を妨げる要因は実質的に消失し、伝導電子１のドリフト速度はバイアス電流Ｉの進行方向の縦成分のみが残る。このことは、縦抵抗率ρｘｘがスピン軌道相互作用に影響されないことを意味する。 Here, the reason why the expression (1) is established will be described based on an intuitive method. As shown in FIG. 1 (a), and the spin polarization P s of conduction electrons 1 having a spin magnetic moment m of the z-direction of 100%, that is, by all the spin of the conduction electrons 1 up, the channel region When a bias current I is applied to δ in the x direction, the orbit of the conduction electron 1 is warped in the same −y direction by the force f SOI caused by the spin orbit interaction. For this reason, charge is biased inside the channel region δ, a Hall electric field E H is generated by the anomalous Hall effect, and the Hall electric force f Hall acts on the conduction electrons 1 in the y direction. In the steady state, the Hall electric force f Hall acting on the conduction electron 1 and the spin-orbit interaction force f SOI are balanced. Therefore, even if the spin-orbit interaction acts on the conduction electron 1, the factor that hinders the straightness of the conduction electron 1 substantially disappears, and the drift velocity of the conduction electron 1 is only the vertical component in the traveling direction of the bias current I. Remain. This means that the longitudinal resistivity ρ xx is not affected by the spin orbit interaction.

一方、図１（ｂ）に示すように、伝導電子１のスピン偏極度Ｐｓを０％にして、チャネル領域δにｘ方向にバイアス電流Ｉを流すとき、チャネル領域δの内部に電荷の偏りは生じない。このとき、ｚ方向のスピン磁気モーメントｍを有するスピンアップした伝導電子１αと、−ｚ方向のスピン磁気モーメント−ｍを有するスピンダウンした伝導電子１βの各電子密度は等しい。電荷の偏りを生じないのは、スピン軌道相互作用による伝導電子１の軌道偏向の向きが、スピンアップした伝導電子１αに対しては−ｙ方向に力ｆＳＯＩが作用し、スピンダウンした伝導電子１βに対してはｙ方向の逆向きに力ｆＳＯＩが作用するからである。このため、伝導電子１のスピン偏極度Ｐｓが０％のときは１００％のときのようにホール電場ＥＨは発生せず、ホール抵抗である横抵抗率ρｙｘはゼロである。従って、定常状態でもスピン軌道相互作用の影響が残り、縦抵抗率ρｘｘはスピン偏極度Ｐｓが１００％のときよりも大きい。 On the other hand, as shown in FIG. 1B, when the spin polarization degree P s of the conduction electron 1 is set to 0% and the bias current I is passed through the channel region δ in the x direction, the charge bias is generated inside the channel region δ. Does not occur. At this time, each electron density of the spin-up conduction electron 1α having the spin magnetic moment m in the z direction is equal to that of the spin-down conduction electron 1β having the spin magnetic moment −m in the −z direction. The reason why the electric charge is not biased is that the direction of the orbital deflection of the conduction electron 1 due to the spin-orbit interaction is such that the force f SOI acts on the spin-up conduction electron 1α in the −y direction and the spin-down conduction electron 1α. This is because the force f SOI acts on 1β in the direction opposite to the y direction. For this reason, when the spin polarization degree P s of the conduction electron 1 is 0%, the Hall electric field E H is not generated as in the case of 100%, and the lateral resistivity ρ yx which is the Hall resistance is zero. Accordingly, the influence of the spin orbit interaction remains even in the steady state, and the longitudinal resistivity ρ xx is larger than when the spin polarization P s is 100%.

以上のことから、縦抵抗率ρｘｘと横抵抗率ρｙｘはともにキャリアのスピン偏極度Ｐｓに依存し、図２に示すように、横抵抗率ρｙｘは、スピン偏極度Ｐｓが１００％のときに最大値、スピン偏極度Ｐｓが０％のときに最小のゼロ、縦抵抗率ρｘｘは、スピン偏極度Ｐｓが１００％のときに最小値、スピン偏極度Ｐｓが０％のときに最大値を示すことが容易に推定できる。従って、横抵抗率ρｙｘの縦抵抗率ρｘｘに対する縦横抵抗率比ρｙｘ／ρｘｘはスピン偏極度Ｐｓに敏感であることが理解され、この縦横抵抗率比ρｙｘ／ρｘｘからスピン偏極度Ｐｓを正確に評価できることが予測される。 From the above, the longitudinal resistivity ρ xx and the lateral resistivity ρ yx both depend on the carrier spin polarization P s , and as shown in FIG. 2, the lateral resistivity ρ yx has a spin polarization P s of 100. % When the spin polarization degree P s is 0%, the minimum is zero, and the longitudinal resistivity ρ xx is the minimum value when the spin polarization degree P s is 100% and the spin polarization degree P s is 0. It can be easily estimated that the maximum value is shown at%. Accordingly, the aspect resistivity ratio vertical resistivity [rho xx lateral resistivity ρ yx ρ yx / ρ xx is understood to be sensitive to the spin polarization P s, spin from this aspect resistivity ratio ρ yx / ρ xx it is expected that the polarization P s can be accurately evaluated.

このたび、発明者は、スピン２流体モデル（A.Fert and I.A. Campbell, Phys. Rev. Lett. 14 (1968) 1190）を使う微視的なモデルに依存しない現象論によって、縦抵抗率ρｘｘ及び横抵抗率ρｙｘに対するスピン偏極度Ｐｓの影響を解析的に計算することにより、任意のスピン偏極度Ｐｓにおける縦抵抗率ρｘｘと横抵抗率ρｙｘとの比の表式を（１）式のように定量的に求めることに成功した。 This time, the inventor has obtained a longitudinal resistivity ρ xx by a phenomenology that does not depend on a microscopic model using a spin two-fluid model (A. Fert and IA Campbell, Phys. Rev. Lett. 14 (1968) 1190). and by calculating analytically the effects of spin polarization P s with respect to the lateral resistivity [rho yx, the ratio of the vertical resistivity [rho xx and horizontal resistivity [rho yx at any spin polarization P s of the expressions ( 1) We succeeded in obtaining quantitatively as shown in the equation.

すなわち、横方向と縦方向でキャリアの同じ散乱過程が同時に存在する場合には、摩擦項がテンソル形式で表現できるので、ドルーデの式は電界Ｅ及び磁界Ｂの存在のもとで次の（３）式のように変形出来る。

Figure 2013134995
In other words, when the same carrier scattering process exists in the horizontal direction and the vertical direction, the friction term can be expressed in a tensor form. Therefore, the Drude equation is expressed by the following (3 It can be transformed as
Figure 2013134995

ここで、ｍ及びｑはキャリアの質量及び電荷量、ｖはキャリアのドリフト速度である。また、Ｓはテンソル量で、τ‖を縦方向のキャリアの散乱緩和時間とすると、Ｓは次の（４）式によって定義される。

Figure 2013134995
Here, m and q are the carrier mass and charge amount, and v is the carrier drift velocity. Further, S is a tensor amount, and S is defined by the following equation (4), where τ と is a vertical carrier scattering relaxation time.
Figure 2013134995

定常状態ではｄｖ／ｄｔ＝０であり、また、磁界Ｂがｚ方向に平行とすると、スピンアップした電子の電気伝導度σα、及びスピンダウンした電子の電気伝導度σβは、それぞれ次の（５）式及び（６）式のように表される。

Figure 2013134995
Figure 2013134995
 In a steady state, dv / dt = 0, and when the magnetic field B is parallel to the z direction, the electrical conductivity σ α of the spin-up electron and the electrical conductivity σ β of the spin-down electron are respectively It is expressed as equations (5) and (6).
Figure 2013134995
Figure 2013134995

また、全体の電気伝導度σは次の（７）式に表される。

Figure 2013134995
The overall electrical conductivity σ is expressed by the following equation (7).
Figure 2013134995

また、一般に、縦抵抗率ρｘｘ及び横抵抗率ρｙｘは電気伝導度の各テンソル成分を用いてそれぞれ次の（８）式及び（９）式に表される。

Figure 2013134995
Figure 2013134995
 In general, the longitudinal resistivity ρ xx and the lateral resistivity ρ yx are expressed by the following equations (8) and (9) using the respective tensor components of electrical conductivity.
Figure 2013134995
Figure 2013134995

このため、（８）式及び（９）式におけるσｘｘ及びσｘｙは、（５）式、（６）式、及び（７）式から、それぞれ次の（１０）式及び（１１）式のように表される。

Figure 2013134995
Figure 2013134995
 Therefore, σ xx and σ xy in the equations (8) and (9) are obtained from the following equations (10) and (11) from the equations (5), (6), and (7), respectively. It is expressed as follows.
Figure 2013134995
Figure 2013134995

この結果、縦抵抗率ρｘｘ及び横抵抗率ρｙｘは、平静時の電気伝導度σα、σβをσα，０＝ｎαｑ２τ‖／ｍ＝ｑｎαμ、σβ，０＝ｎβｑ２τ‖／ｍ＝ｑｎβμとすると、それぞれ次の（１２）式及び（１３）式に表される。

Figure 2013134995
Figure 2013134995
 As a result, the longitudinal resistivity ρ xx and the lateral resistivity ρ yx are obtained by changing the electrical conductivities σ α and σ β at the time of calm to σ α, 0 = n α q 2 τ‖ / m = qn α μ, σ β, 0 = When n β q 2 τ || / m = qn β μ, are expressed in the following equation (12) and (13).
Figure 2013134995
Figure 2013134995

ここで、本実施の形態のスピン偏極度測定方法では、磁界Ｂを印加せず、Ｂ＝０なので、（１２）式及び（１３）式中のＢを０とすると、縦抵抗率ρｘｘ及び横抵抗率ρｙｘはそれぞれ次の（１４）式及び（１５）式に表される。

Figure 2013134995
Figure 2013134995
 Here, in the spin polarization measurement method of the present embodiment, since the magnetic field B is not applied and B = 0, assuming that B in the equations (12) and (13) is 0, the longitudinal resistivity ρ xx and The lateral resistivity ρ yx is expressed by the following equations (14) and (15), respectively.
Figure 2013134995
Figure 2013134995

前述した（１）式は、上記の（１５）式を（１４）式で割ることで導かれ、（１）式で表される原理によってスピン偏極度Ｐｓの相対値測定が前述したように可能になっている。 The above-described equation (1) is derived by dividing the above equation (15) by the equation (14). As described above, the relative value measurement of the spin polarization degree P s is performed according to the principle represented by the equation (1). It is possible.

また、スピン偏極度Ｐｓが０％のときの縦抵抗率ρｘｘ（Ｐｓ＝０）は、（１２）式中のＰｓ＝０と置くことで、次の（１６）式で表される。

Figure 2013134995
Further, the longitudinal resistivity ρ xx (P s = 0) when the spin polarization degree P s is 0% is expressed by the following equation (16) by setting P s = 0 in the equation (12). The
Figure 2013134995

また、スピン偏極度Ｐｓが１００％のときの縦抵抗率ρｘｘ（Ｐｓ＝１）は、（１２）式中のＰｓ＝１と置くことで、次の（１７）式で表される。

Figure 2013134995
Further, the longitudinal resistivity ρ xx (P s = 1) when the spin polarization P s is 100% is expressed by the following equation (17) by setting P s = 1 in the equation (12). The
Figure 2013134995

従って、（１４）式から以下の（１８）式を次のように導くことが出来る。

Figure 2013134995
Therefore, the following equation (18) can be derived from the equation (14) as follows.
Figure 2013134995

また、（１）式から次の（１９）式が導かれる。

Figure 2013134995
Further, the following equation (19) is derived from the equation (1).
Figure 2013134995

このため、上記の（１９）式に（１８）式を代入すると、次の（２０）式が得られる。

Figure 2013134995
For this reason, the following equation (20) is obtained by substituting the equation (18) into the above equation (19).
Figure 2013134995

この（２０）式は、スピン偏極度Ｐｓが０％のときの縦抵抗率ρｘｘ（Ｐｓ＝０）の、スピン偏極度Ｐｓが１００％のときの縦抵抗率ρｘｘ（Ｐｓ＝１）に対する比から１を減算した減算値で、或るスピン偏極度Ｐｓにおける縦横抵抗率比ρｙｘ／ρｘｘの二乗値を割った値が、そのスピン偏極度Ｐｓの二乗値に等しい関係にあることを、表す。本実施の形態のスピン偏極度測定方法では、この関係に基づいて、被測定材料のスピン偏極度Ｐｓの絶対値を評価する。 The (20), the vertical resistivity when spin polarization P s is 0% [rho xx of (P s = 0), vertical resistivity when spin polarization P s of 100% ρ xx (P s = 1) is a subtracted value obtained by subtracting 1 from the ratio of the ratio of the longitudinal and lateral resistivity ratios ρ yx / ρ xx at a certain spin polarization degree P s to the square value of the spin polarization degree P s Indicates that they are in an equal relationship. The spin polarization measuring method of this embodiment, on the basis of this relationship, to evaluate the absolute value of the spin polarization P s of the material being measured.

スピン偏極度Ｐｓが０％の電流を非磁性チャネル領域δに注入したときの縦抵抗率ρｘｘ（Ｐｓ＝０）は実測可能であり、スピン偏極度Ｐｓが１００％のときの電流を非磁性チャネル領域δに注入した縦抵抗率ρｘｘ（Ｐｓ＝１）も原理的に評価可能である。従って、或るスピン偏極度Ｐｓにおける縦横抵抗率比ρｙｘ／ρｘｘとそのスピン偏極度Ｐｓとの比例係数である積μＳは、スピン偏極度Ｐｓが０％及び１００％のときの縦抵抗率ρｘｘ（Ｐｓ＝０）及びρｘｘ（Ｐｓ＝１）から原理上実測できることが理解される。この結果、縦横抵抗率比ρｙｘ／ρｘｘ、縦抵抗率ρｘｘ（Ｐｓ＝０）、及び縦抵抗率ρｘｘ（Ｐｓ＝１）の３種類の測定値を（２０）式に代入することで、上記のように、スピン偏極度Ｐｓの絶対値を評価することが出来る。 The longitudinal resistivity ρ xx (P s = 0) when a current having a spin polarization P s of 0% is injected into the nonmagnetic channel region δ can be measured, and the current when the spin polarization P s is 100%. The longitudinal resistivity ρ xx (P s = 1) in which is implanted into the nonmagnetic channel region δ can be evaluated in principle. Therefore, the product μS is a proportionality coefficient aspect resistivity ratio at a certain spin polarization P s ρ yx / ρ xx and its spin polarization P s is the spin polarization P s is at 0% and 100% It is understood that the longitudinal resistivity ρ xx (P s = 0) and ρ xx (P s = 1) can be measured in principle. As a result, three types of measured values of the vertical / horizontal resistivity ratio ρ yx / ρ xx , the longitudinal resistivity ρ xx (P s = 0), and the longitudinal resistivity ρ xx (P s = 1) are substituted into the equation (20). doing, as mentioned above, it is possible to evaluate the absolute value of the spin polarization P s.

縦横抵抗率比ρｙｘ／ρｘｘは、例えば、図３に示すように、被測定材料２に非磁性導体３を接合した素子の両端に電圧を印加して電流Ｉを流し、被測定材料２から非磁性導体３にスピン偏極電流Ｉｓｐｉｎを注入して、測定する。このとき、非磁性導体３のチャネル領域δにおけるスピン偏極電流Ｉｓｐｉｎの進行方向に平行な縦方向電界Ｅｘ及びこれに垂直な横方向電界Ｅｙは、スピン偏極電流Ｉｓｐｉｎの縦方向電流密度をｉｘ、横方向電流密度をｉｙとすると、次の（２１）式で表される。

Figure 2013134995
For example, as shown in FIG. 3, the longitudinal / lateral resistivity ratio ρ yx / ρ xx applies a voltage to both ends of an element in which a nonmagnetic conductor 3 is bonded to a material to be measured 2 to cause a current I to flow. Then, a spin-polarized current I spin is injected into the nonmagnetic conductor 3 and measured. At this time, the longitudinal electric field E x parallel to the traveling direction of the spin-polarized current I spin and the transverse electric field E y perpendicular to the traveling direction of the spin-polarized current I spin in the channel region δ of the nonmagnetic conductor 3 are equal to the longitudinal direction of the spin-polarized current I spin . When the current density is i x and the lateral current density is i y , the following equation (21) is obtained.
Figure 2013134995

この（２１）式で横方向電流密度ｉｙを０（ｉｙ＝０）とすると、縦抵抗率ρｘｘ及び横抵抗率ρｙｘはそれぞれ次の（２２）式に表される。

Figure 2013134995
Assuming that the horizontal current density i y is 0 (i y = 0) in the equation (21), the longitudinal resistivity ρ xx and the lateral resistivity ρ yx are expressed by the following equations (22), respectively.
Figure 2013134995

このため、非磁性導体３におけるスピン偏極電流Ｉｓｐｉｎの進行方向に平行な縦方向電圧Ｖｘを電圧計Ｖ１で測定し、縦方向電圧Ｖｘを縦方向電流Ｉｘの電流値で割った値を非磁性導体３の縦抵抗Ｒ‖とする。また、スピン偏極電流Ｉｓｐｉｎの進行方向に垂直な横方向電圧Ｖｙを電圧計Ｖ２で測定し、横方向電圧Ｖｙを縦方向電流Ｉｘの電流値で割った値を非磁性導体３の横抵抗Ｒ⊥とする。そして、横抵抗Ｒ⊥を縦抵抗Ｒ‖で割った値に、非磁性導体３の幅Ｗを乗じて、非磁性導体３の長さＬで割ることで、縦横抵抗率比ρｙｘ／ρｘｘが得られる。 For this reason, the longitudinal voltage V x parallel to the traveling direction of the spin-polarized current I spin in the nonmagnetic conductor 3 is measured by the voltmeter V 1 , and the longitudinal voltage V x is divided by the current value of the longitudinal current I x. This value is taken as the longitudinal resistance R ‖ of the nonmagnetic conductor 3. In addition, the lateral voltage V y perpendicular to the traveling direction of the spin-polarized current I spin is measured with the voltmeter V 2 , and the value obtained by dividing the lateral voltage V y by the current value of the longitudinal current I x is a nonmagnetic conductor. 3 of the lateral resistor R ⊥. Then, the value obtained by dividing the lateral resistance R ⊥ in the vertical resistor R ‖, multiplied by the width W of the nonmagnetic conductor 3, by dividing the length L of the nonmagnetic conductor 3, the aspect resistivity ratio ρ yx / ρ xx Is obtained.

このような本実施の形態のスピン偏極度測定方法によれば、導電性を有する被測定材料２に接合された非磁性導体３のチャネル領域δを流れるスピン偏極電流の進行方向に沿う縦方向の縦抵抗率ρｘｘ、及びこれに直交する横方向の横抵抗率ρｙｘを測定することで、測定した横抵抗率ρｙｘの縦抵抗率ρｘｘに対する縦横抵抗率比ρｙｘ／ρｘｘと非磁性導体３におけるキャリアのスピン偏極度Ｐｓとが比例関係にあることに基づいて、縦横抵抗率比ρｙｘ／ρｘｘから被測定材料２のスピン偏極度Ｐｓの相対値を評価することが出来る。 According to the spin polarization measuring method of this embodiment as described above, the vertical direction along the traveling direction of the spin polarization current flowing through the channel region δ of the nonmagnetic conductor 3 bonded to the conductive material 2 to be measured. vertical resistivity [rho xx, and by measuring the transverse horizontal resistivity [rho yx perpendicular thereto, and aspect resistivity ratio ρ yx / ρ xx with respect to the longitudinal resistivity [rho xx of the measured horizontal resistivity [rho yx The relative value of the spin polarization P s of the material 2 to be measured is evaluated from the longitudinal / lateral resistivity ratio ρ yx / ρ xx based on the fact that the carrier spin polarization P s in the nonmagnetic conductor 3 is proportional. I can do it.

このときの比例係数は、被測定材料２とチャネル領域δの測定点までの距離が有限なため（１）式における積μＳより小さくなるが、チャネル領域δの材料を変えない限り同じである。つまり、チャネル領域δで観測される縦横抵抗率比ρｙｘ／ρｘｘは、被測定材料２の材料のみに依存するので、被測定材料２のスピン偏極度Ｐｓが相対測定できる。例えば、被測定材料２Ｙについての縦横抵抗率比ρｙｘ／ρｘｘがａ、被測定材料２Ｚについての縦横抵抗率比ρｙｘ／ρｘｘがｂとして得られた場合、ａとｂは一般に異なる値を示すが、その違いはそれぞれの被測定材料２Ｙ、２Ｚのスピン偏極度Ｐｓの違いだけに由来するので、被測定材料２Ｙ、２Ｚのスピン偏極度Ｐｓが相対測定できる。 The proportionality coefficient at this time is smaller than the product μS in the equation (1) because the distance between the measured material 2 and the measurement point of the channel region δ is finite, but is the same as long as the material of the channel region δ is not changed. That is, since the longitudinal / lateral resistivity ratio ρ yx / ρ xx observed in the channel region δ depends only on the material of the material to be measured 2, the spin polarization degree P s of the material to be measured 2 can be relatively measured. For example, when the longitudinal / lateral resistivity ratio ρ yx / ρ xx for the material to be measured 2Y is obtained as a and the longitudinal / lateral resistivity ratio ρ yx / ρ xx for the material to be measured 2Z is obtained as b, a and b are generally different values. are illustrated, the difference is each of the measured material 2Y, since derived from only the difference in spin polarization P s of 2Z, material being measured 2Y, spin polarization P s of 2Z can be relative measurements.

このため、従来のスピン偏極トンネリング効果を用いたスピン偏極度測定方法のように被測定材料２が強磁性体に限られることはなく、また、従来のアンドレーフ反射を利用したスピン偏極度測定方法のように被測定材料２が金属に限られることはなく、被測定材料２は導電性を持ちさえすれば、被測定材料２に接合された非磁性導体３のチャネル領域δの横抵抗率ρｙｘと縦抵抗率ρｘｘを測定するだけで、金属か半導体かに依らず、被測定材料２のスピン偏極度Ｐｓを評価することが可能になる。しかも、従来のアンドレーフ反射を利用したスピン偏極度測定方法のように、被測定材料全体を超伝導状態に達するまで冷却する必要もなく、任意の測定周囲温度で、キャリアのスピン偏極度Ｐｓを評価することが可能になる。また、キャリアが２種類の強磁性層を通過する従来のスピン偏極トンネリング効果を用いた測定方法と異なり、測定中にキャリアのスピン偏極度Ｐｓの値が変化しないことが保証される。さらに、大がかりなＳＴＭ技術を必要とせず、普通の電流測定と同様な手軽さでスピン偏極度Ｐｓを測定することが出来るため、スピン偏極度Ｐｓの測定を簡便に行ってその測定結果を後述する論理ゲートのような新たな回路素子へ応用することが可能になる。 Therefore, the material to be measured 2 is not limited to a ferromagnetic material as in the conventional spin polarization measurement method using the spin polarization tunneling effect, and the conventional spin polarization measurement method using Andreff reflection is used. The material to be measured 2 is not limited to metal as in the case of the above. As long as the material to be measured 2 has conductivity, the lateral resistivity ρ of the channel region δ of the nonmagnetic conductor 3 joined to the material to be measured 2 is not limited. Only by measuring yx and longitudinal resistivity ρ xx , it is possible to evaluate the spin polarization P s of the material 2 to be measured regardless of whether it is a metal or a semiconductor. In addition, unlike the conventional spin polarization measurement method using Andreff reflection, there is no need to cool the entire material to be measured until it reaches the superconducting state, and the spin polarization P s of the carrier can be set at any measurement ambient temperature. It becomes possible to evaluate. Further, unlike the conventional measurement method using the spin-polarized tunneling effect in which carriers pass through two types of ferromagnetic layers, it is guaranteed that the value of the carrier spin-polarization degree P s does not change during measurement. Furthermore, since the spin polarization degree P s can be measured with the same ease as ordinary current measurement without requiring a large-scale STM technique, the measurement of the spin polarization degree P s can be performed easily. It becomes possible to apply to a new circuit element such as a logic gate described later.

また、本実施の形態のスピン偏極度測定方法によれば、チャネル領域δの縦横抵抗率比ρｙｘ／ρｘｘに加えて、スピン偏極度Ｐｓが０％及び１００％の電流を非磁性チャネル領域に注入したときの各縦抵抗率ρｘｘ（Ｐｓ＝０）及びρｘｘ（Ｐｓ＝１）を測定することで、これら各特性値の予め導かれている（２０）式の関係に基づいて、チャネル領域δのスピン偏極度Ｐｓの絶対値、ひいては後述する方法によって被測定材料２のスピン偏極度の絶対値を評価することが出来る。このため、従来のスピン偏極トンネリング効果を用いたスピン偏極度測定方法のように、２種類の強磁性層のうちの一方の強磁性層のスピン偏極度Ｐｓを予め決定しておく必要もなく、簡易にスピン偏極度Ｐｓの絶対値を評価することが出来る。 Further, according to the spin polarization measuring method of the present embodiment, in addition to the longitudinal / lateral resistivity ratio ρ yx / ρ xx of the channel region δ, a current having a spin polarization degree P s of 0% and 100% is applied to the nonmagnetic channel. By measuring each longitudinal resistivity ρ xx (P s = 0) and ρ xx (P s = 1) when injected into the region, the relationship of these characteristic values derived in advance in equation (20) is satisfied. Based on this, the absolute value of the spin polarization degree P s of the channel region δ, and hence the absolute value of the spin polarization degree of the material 2 to be measured can be evaluated by the method described later. For this reason, the spin polarization degree P s of one of the two types of ferromagnetic layers needs to be determined in advance as in the conventional spin polarization measurement method using the spin polarization tunneling effect. no, it is possible to evaluate the absolute value of the spin polarization P s in a simple manner.

また、本実施の形態のスピン偏極度測定方法によれば、被測定材料２から非磁性導体３に注入したスピン偏極電流Ｉｓｐｉｎの進行方向に対して平行及び垂直な縦方向電圧Ｖｘ及び横方向電圧Ｖｙを測定し、測定した各電圧Ｖｘ，Ｖｙの値を注入したスピン偏極電流Ｉｓｐｉｎの縦方向電流Ｉｘの電流値で割ることで、縦抵抗Ｒ‖及び横抵抗Ｒ⊥の値を求めることが出来る。このため、キャリアの走行状態に摂動を加えずにスピン偏極度Ｐｓの評価を行うことが可能になる。 Further, according to the spin polarization measuring method of the present embodiment, the longitudinal voltage V x parallel and perpendicular to the traveling direction of the spin polarization current I spin injected from the material 2 to be measured into the nonmagnetic conductor 3 and By measuring the lateral voltage V y and dividing the measured values of the voltages V x and V y by the current value of the longitudinal current I x of the injected spin polarization current I spin , the longitudinal resistance R ‖ and the lateral resistance The value of R ⊥ can be obtained. It is therefore possible to evaluate the spin polarization P s without adding perturbation to the running state of the carrier.

次に、被測定材料におけるキャリアのスピン偏極度Ｐｓを測定する本発明によるスピン偏極度測定メータの一実施の形態について説明する。 Next, one embodiment of the spin polarization measurement meter according to the invention for measuring the spin polarization P s of carriers in the material being measured.

上記の図３は、この一実施の形態によるスピン偏極度測定メータ１１の構成の概略斜視図である。   FIG. 3 is a schematic perspective view of the configuration of the spin polarization measurement meter 11 according to this embodiment.

スピン偏極度測定メータ１１は、導電性を有する被測定材料２に非磁性導体３が接合されたメータ本体１２から構成される。スピン偏極度Ｐｓの測定対象である被測定材料２はスピン偏極源として用いられる。また、非磁性導体３としてはＰｔ、Ｐｄなどの非磁性金属が用いられ、その長さＬａはスピン自然拡散長よりも短く設定される。上述したように、積μＳはスピン偏極度Ｐｓの検出感度を与えるため、スピン偏極度Ｐｓの測定における検出感度を上げるには、高いキャリア移動度μとスピン軌道相互作用の強さＳが大きな材料の非磁性導体３を用いると、有効である。また、スピン偏極度測定メータ１１は、第１の電圧測定手段として電圧計Ｖ１、第２の電圧測定手段として電圧計Ｖ２を備える。 The spin polarization measuring meter 11 is composed of a meter main body 12 in which a nonmagnetic conductor 3 is bonded to a conductive material 2 to be measured. Measured material 2, which is a measurement target of the spin polarization P s is used as a spin Henkyokugen. The nonmagnetic conductor 3 is made of a nonmagnetic metal such as Pt or Pd, and its length La is set shorter than the spin natural diffusion length. As described above, since the product μS is to provide a detection sensitivity of the spin polarization P s, to raise the detection sensitivity in the measurement of the spin polarization P s, the intensity S of the high carrier mobility μ and the spin-orbit interaction It is effective to use a nonmagnetic conductor 3 made of a large material. The spin polarization measuring meter 11 includes a voltmeter V 1 as a first voltage measuring means and a voltmeter V 2 as a second voltage measuring means.

スピン偏極度測定メータ１１の両端に電圧を印加すると、被測定材料２から非磁性導体３にスピン偏極電流Ｉｓｐｉｎが注入される。電圧計Ｖ１は、被測定材料２から距離Ｌａ離れた地点における非磁性導体３の、スピン偏極電流Ｉｓｐｉｎの進行方向に平行な縦方向電圧Ｖｘを測定する。また、電圧計Ｖ２は、非磁性導体３の、スピン偏極電流Ｉｓｐｉｎの進行方向に垂直な横方向電圧Ｖｙを測定する。測定した縦方向電圧Ｖｘ及び横方向電圧Ｖｙをスピン偏極電流Ｉｓｐｉｎの縦方向電流Ｉｘでそれぞれ割った値を被測定材料２に接続した非磁性チャネル領域δの縦抵抗Ｒ‖及び横抵抗Ｒ⊥とし、横抵抗Ｒ⊥を縦抵抗Ｒ‖で割った値に、非磁性導体３の幅Ｗを乗じて、非磁性導体３の長さＬaで割ることで、縦横抵抗率比ρｙｘ／ρｘｘ を求める。そして、求めた縦横抵抗率比ρｙｘ／ρｘｘ 、並びに非磁性導体３にスピン偏極度Ｐｓが０％及び１００％の電流を注入したときの各縦抵抗率ρｘｘ（Ｐｓ＝０）及びρｘｘ（Ｐｓ＝１）の値を（２０）式に代入することで、被測定材料２から距離Ｌａ離れた地点における非磁性導体３のスピン偏極度Ｐｓの絶対値を算出することが出来る。 When a voltage is applied to both ends of the spin polarization measurement meter 11, a spin polarization current I spin is injected from the material to be measured 2 into the nonmagnetic conductor 3. The voltmeter V 1 measures a longitudinal voltage V x parallel to the traveling direction of the spin-polarized current I spin of the nonmagnetic conductor 3 at a point away from the material to be measured 2 by a distance La. The voltmeter V 2 measures a lateral voltage V y of the nonmagnetic conductor 3 perpendicular to the traveling direction of the spin-polarized current I spin . A value obtained by dividing the measured longitudinal voltage V x and transverse voltage V y by the longitudinal current I x of the spin polarized current I spin , respectively, and the longitudinal resistance R の of the nonmagnetic channel region δ connected to the material 2 to be measured and lateral resistance R ⊥, the value obtained by dividing the lateral resistance R ⊥ in the vertical resistor R ‖, multiplied by the width W of the nonmagnetic conductor 3, by dividing a non-magnetic conductor 3 of the length La, the aspect resistivity ratio ρ yx / ρ xx is obtained. Then, the obtained aspect resistivity ratio ρ yx / ρ xx, as well as the non-magnetic conductor 3 in spin polarization P s is 0% and 100% of each vertical resistivity when current was injected ρ xx (P s = 0) And the value of ρ xx (P s = 1) are substituted into the equation (20) to calculate the absolute value of the degree of spin polarization P s of the nonmagnetic conductor 3 at a point La away from the material 2 to be measured. I can do it.

ここで、スピン偏極度０％の電流を非磁性導体３に注入するためには、被測定材料２の代わりに、非磁性導体３と同じ材料を使い、スピン偏極度１００％の電流を非磁性導体３に注入するためには、被測定材料２の代わりに、ホイスラー合金（ハーフメタル）を用いる。   Here, in order to inject a current with a spin polarization of 0% into the nonmagnetic conductor 3, the same material as the nonmagnetic conductor 3 is used instead of the material 2 to be measured, and a current with a spin polarization of 100% is nonmagnetic. In order to inject into the conductor 3, a Heusler alloy (half metal) is used instead of the material 2 to be measured.

被測定材料２のスピン偏極度Ｐ’ｓは、スピン偏極度測定メータ１１を用いて上記のように得られた非磁性チャネル領域δのスピン偏極度Ｐｓが図４（ａ）に示す較正器２１を用いて較正されることで、求められる。較正器２１は、被測定材料２に相当するスピン偏極源２ａとして、スピン偏極度Ｐｓが１００％の材料、例えば、ホイスラー合金（ハーフメタル）が使われる。また、非磁性導体３に相当する試料３ａは、非磁性導体３に用いられる材料からなり、同図に示すような、長さＬａよりも充分大きな長さＬｂを有する。 Spin polarization P 's of the measured material 2, calibrator spin polarization P s of the non-magnetic channel regions δ obtained as described above using the spin polarization measurement meter 11 is shown in FIG. 4 (a) It is calculated | required by being calibrated using 21. Calibrator 21, as a spin Henkyokugen 2a corresponding to the measured material 2, spin polarization P s of 100% of the material, for example, Heusler alloy (half metal) is used. A sample 3a corresponding to the nonmagnetic conductor 3 is made of a material used for the nonmagnetic conductor 3, and has a length Lb sufficiently larger than the length La as shown in FIG.

この構成の較正器２１において、較正器２１の両端に電圧を印加して電流Ｉを流し、ソース電極としてのスピン偏極源２ａから試料３ａにスピン偏極電流Ｉｓｐｉｎを注入する。そして、そのときの試料３ａの各長さＬｘ、つまり、スピン偏極源２ａからの各距離Ｌｘにおける縦方向電圧Ｖｘを各電圧計Ｖ１ａ、Ｖ１ｂ及びＶ１ｃによって測定し、横方向電圧Ｖｙを各電圧計Ｖ２ａ、Ｖ２ｂ及びＶ２ｃによって測定することで、試料３ａの各長さＬｘにおける縦抵抗Ｒ‖及び横抵抗Ｒ⊥の各値を測定する。 In the calibrator 21 having this configuration, a voltage I is applied to both ends of the calibrator 21 to cause a current I to flow, and a spin-polarized current I spin is injected from the spin-polarized source 2a serving as a source electrode into the sample 3a. Each length Lx of the sample 3a at that time, that is, the longitudinal voltage V x at each distance Lx from the spin Henkyokugen 2a measured by the voltmeter V 1a, V 1b and V 1c, transverse voltage V y each voltmeter V 2a, by measuring the V 2b and V 2c, measuring each value of the vertical resistance R ‖ and transverse resistance R ⊥ in the length Lx of the sample 3a.

そして、この測定で得られた縦抵抗Ｒ‖及び横抵抗Ｒ⊥の各値から、チャネル幅と長さに考慮して各距離Ｌｘにおける縦横抵抗率比ρｙｘ／ρｘｘ を求める。さらに、求めた縦横抵抗率比ρｙｘ／ρｘｘ 、並びに、既に得られているスピン偏極度Ｐｓが０％および１００％のときの試料３ａの各縦抵抗率ρｘｘ（Ｐｓ＝０）及びρｘｘ（Ｐｓ＝１）の値を（２０）式に代入し、各距離Ｌｘにおける試料３ａのスピン偏極度Ｐｓを算出する。同図（ｂ）は、この算出結果をグラフに表したものである。同グラフの横軸はスピン偏極源２ａからの距離Ｌｘ、縦軸はスピン偏極度Ｐｓを表す。同グラフに示されるように、スピン偏極度Ｐｓは、スピン偏極源２ａから離れるのに従って漸減するパターンのカーブ特性を有する。図３に示すスピン偏極度測定メータ１１に用いられる非磁性導体３の長さＬａは、自然対数の底をｅとすると、スピン偏極度Ｐｓが１／ｅ（＝約１／２．７）に低減する距離、つまり、スピン自然拡散長よりも短く設定される（Ｌａ＜スピン自然拡散長）。 Then, the longitudinal and lateral resistivity ratio ρ yx / ρ xx at each distance Lx is obtained from the values of the longitudinal resistance R ‖ and lateral resistance R 得 obtained in this measurement in consideration of the channel width and length. Further, the obtained longitudinal and lateral resistivity ratio ρ yx / ρ xx , and the longitudinal resistivity ρ xx (P s = 0) of the sample 3a when the spin polarization degree P s already obtained is 0% and 100%. And the value of ρ xx (P s = 1) is substituted into the equation (20), and the spin polarization degree P s of the sample 3a at each distance Lx is calculated. FIG. 5B shows the calculation result in a graph. The horizontal axis of the graph represents the distance Lx from the spin Henkyokugen 2a, the vertical axis represents spin polarization P s. As shown in the graph, the spin polarization degree P s has a curve characteristic of a pattern that gradually decreases as the distance from the spin polarization source 2a increases. The length La of the nonmagnetic conductor 3 used in the spin polarization measurement meter 11 shown in FIG. 3 is such that the spin polarization P s is 1 / e (= about 1 / 2.7), where e is the base of the natural logarithm. Is set to be shorter than the spin natural diffusion length (La <spin natural diffusion length).

図３に示すスピン偏極度測定メータ１１では、被測定材料２から距離Ｌａ離れた地点における非磁性導体３のスピン偏極度Ｐ’ｓ（Ｌａ）を得ることが出来るが、上記較正器２１で得た結果を使うことで、スピン偏極度測定メータ１１で得たスピン偏極度Ｐ’ｓ（Ｌａ）から、被測定材料２からの距離０におけるスピン偏極度Ｐｓ、つまり、被測定材料２のスピン偏極度Ｐ’ｓ（０）を得ることが出来る。すなわち、上記較正器２１で得た距離Ｌａにおけるスピン偏極度Ｐｓ（Ｌa）に対するスピン偏極度測定メータ１１で得た距離Ｌａにおけるスピン偏極度Ｐ’ｓ（Ｌａ）の比が、被測定材料２のスピン偏極度Ｐ’ｓに等しい。 In the spin polarization measurement meter 11 shown in FIG. 3, the spin polarization degree P ′ s (La) of the nonmagnetic conductor 3 at a point away from the material to be measured 2 by the distance La can be obtained. results by using, from the spin polarization P 's obtained in spin polarization measurement meter 11 (La), spin polarization P s at the distance 0 from the measured material 2, that is, of the measured material 2 spin The degree of polarization P ′ s (0) can be obtained. That is, the ratio of the spin polarization P ′ s (La) at the distance La obtained by the spin polarization measurement meter 11 to the spin polarization P s (La) at the distance La obtained by the calibrator 21 is the measured material 2 Is equal to the degree of spin polarization P ′ s .

このような本実施の形態によるスピン偏極度測定メータ１１によれば、メータ本体１２の両端に電圧を印加してメータ本体１２における被測定材料２から非磁性導体３にスピン偏極電流Ｉｓｐｉｎを注入し、注入したスピン偏極電流Ｉｓｐｉｎの進行方向に平行及び垂直な縦方向電圧Ｖｘ及び横方向電圧Ｖｙを電圧計Ｖ１及びＶ２で測定することで、縦抵抗Ｒ‖及び横抵抗Ｒ⊥の値を求めることが出来る。このため、キャリアの走行状態に摂動を加えずにスピン偏極度Ｐｓの評価を簡便に行うことが可能なスピン偏極度測定メータ１１が提供される。従って、本実施の形態によるスピン偏極度測定メータ１１は、原理上、実際のスピントロニクスデバイスにおけるリード線やソース−ドレイン電極間のスピン偏極度Ｐｓを、通常の電流計による電流測定と同様な手軽さと精度で、簡易にその場で測定できる能力を有している。 According to the spin polarization measuring meter 11 according to the present embodiment, a voltage is applied to both ends of the meter body 12 so that the spin polarization current I spin is applied from the material to be measured 2 to the nonmagnetic conductor 3 in the meter body 12. By measuring the longitudinal voltage V x and the lateral voltage V y parallel to and perpendicular to the traveling direction of the injected spin-polarized current I spin with the voltmeters V 1 and V 2 , the longitudinal resistance R ‖ and lateral the value of the resistor R ⊥ can be obtained. Therefore, the spin polarization P s conveniently spin polarization measurement meter 11 capable of performing evaluation of without adding perturbation to the running state of the carrier. Therefore, in principle, the spin polarization measuring meter 11 according to the present embodiment can easily measure the spin polarization degree P s between the lead wire and the source-drain electrodes in an actual spintronic device by the same method as the current measurement by a normal ammeter. It has the ability to measure on the spot easily with high accuracy.

次に、上記のスピン偏極度測定メータ１１を用いた本発明による論理演算ゲートの一実施の形態について説明する。   Next, an embodiment of a logical operation gate according to the present invention using the spin polarization measuring meter 11 will be described.

図５は、この一実施の形態による論理演算ゲート３１の構成の概略斜視図である。   FIG. 5 is a schematic perspective view of the configuration of the logical operation gate 31 according to this embodiment.

論理演算ゲート３１は、第１のスピン偏極度測定メータ１１Ａと第２のスピン偏極度測定メータ１１Ｂと第３のスピン偏極度測定メータ１１Ｃとを備えて構成されている。   The logical operation gate 31 includes a first spin polarization measurement meter 11A, a second spin polarization measurement meter 11B, and a third spin polarization measurement meter 11C.

第１のスピン偏極度測定メータ１１Ａは、導電性を有する第１の導電材料２Ａに第１の非磁性導体３Ａが異種接合された第１のメータ本体１２Ａから構成される。第１のメータ本体１２Ａの両端に電圧を印加して入力電流Ｉ１を流し、第１の導電材料２Ａから第１の非磁性導体３Ａに第１のスピン偏極電流ＩSPIN１を注入する。第１の電圧測定手段を構成する電圧計Ｖ１Ａは、注入された第１のスピン偏極電流ＩSPIN１の進行方向に平行な縦方向電圧Ｖｘを測定する。第２の電圧測定手段を構成する電圧計Ｖ２Ａは、第１のスピン偏極電流ＩSPIN１の進行方向に垂直な横方向電圧Ｖｙを測定する。 The first spin polarization degree measurement meter 11A includes a first meter body 12A in which a first nonmagnetic conductor 3A is heterogeneously bonded to a conductive first conductive material 2A. By applying a voltage across the first meter body 12A flowed input current I 1, injected the first spin-polarized current I SPIN1 of a first conductive material 2A in the first non-magnetic conductor 3A. The voltmeter V 1A constituting the first voltage measuring means measures the longitudinal voltage V x parallel to the traveling direction of the injected first spin polarized current I SPIN1 . The voltmeter V 2A constituting the second voltage measuring means measures a lateral voltage V y perpendicular to the traveling direction of the first spin-polarized current I SPIN1 .

また、第２のスピン偏極度測定メータ１１Ｂは、導電性を有する第２の導電材料２Ｂに第２の非磁性導体３Ｂが異種接合された第２のメータ本体１２Ｂから構成される。第２のメータ本体１２Ｂの両端に電圧を印加して入力電流Ｉ２を流し、第２の導電材料２Ｂから第２の非磁性導体３Ｂに第２のスピン偏極電流ＩSPIN２を注入する。第３の電圧測定手段を構成する電圧計Ｖ１Ｂは、注入された第２のスピン偏極電流ＩSPIN２の進行方向に平行な縦方向電圧Ｖｘを測定する。第４の電圧測定手段を構成する電圧計Ｖ２Ｂは、第２のスピン偏極電流ＩSPIN２の進行方向に垂直な横方向電圧Ｖｙを測定する。 The second spin polarization measuring meter 11B includes a second meter body 12B in which a second nonmagnetic conductor 3B is heterogeneously bonded to a conductive second conductive material 2B. By applying a voltage across the second meter body 12B flowed input current I 2, injecting a second spin-polarized current I SPIN2 of a second conductive material 2B in the second non-magnetic conductor 3B. The voltmeter V 1B constituting the third voltage measuring means measures the longitudinal voltage V x parallel to the traveling direction of the injected second spin-polarized current I SPIN2 . Voltmeter V 2B constituting the fourth voltage measuring unit measures a vertical transverse voltage V y in the traveling direction of the second spin-polarized current I SPIN2.

また、第３のスピン偏極度測定メータ１１Ｃは、第３のメータ本体１２Ｃから構成される。第３のメータ本体１２Ｃは第３の非磁性導体３Ｃからなり、第３の非磁性導体３Ｃには第１の非磁性導体３Ａ及び第２の非磁性導体３Ｂが同種接合されている。なお、これら第１、第２及び第３の各非磁性導体３Ａ、３Ｂ及び３Ｃを一体成形し、接合部分を無くしてもよい。第３の非磁性導体３Ｃには、第１の非磁性導体３Ａ及び第２の非磁性導体３Ｂから第１のスピン偏極電流ＩSPIN１及び第２のスピン偏極電流ＩSPIN２が流入し、第３のスピン偏極電流ＩSPIN３が流れる。この第３のスピン偏極電流ＩSPIN３は、第１のスピン偏極電流ＩSPIN１及び第２のスピン偏極電流ＩSPIN２が合成して形成されるものであり、第３の非磁性導体３Ｃから電流Ｉ３として出力される。第５の電圧測定手段を構成する電圧計Ｖ１Ｃは、第３のスピン偏極電流ＩSPIN３の進行方向に平行な縦方向電圧Ｖｘを測定する。第６の電圧測定手段を構成する電圧計Ｖ２Ｃは、第３のスピン偏極電流ＩSPIN３の進行方向に垂直な横方向電圧Ｖｙを測定する。 The third spin polarization degree measurement meter 11C is composed of a third meter body 12C. The third meter main body 12C includes a third nonmagnetic conductor 3C, and the first nonmagnetic conductor 3A and the second nonmagnetic conductor 3B are jointly joined to the third nonmagnetic conductor 3C. The first, second, and third nonmagnetic conductors 3A, 3B, and 3C may be integrally formed to eliminate the joint portion. The third non-magnetic conductor 3C, the first spin-polarized current I SPIN1 and second spin-polarized current I SPIN2 flows from the first non-magnetic conductor 3A and a second non-magnetic conductor 3B, the 3 spin-polarized current I SPIN3 flows. This third spin-polarized current I Spin3 is for the first spin-polarized current I SPIN1 and second spin-polarized current I SPIN2 is formed by combining the third nonmagnetic conductor 3C It is output as a current I 3. The voltmeter V 1C constituting the fifth voltage measuring means measures the longitudinal voltage V x parallel to the traveling direction of the third spin-polarized current I SPIN3 . Voltmeter V 2C constituting the voltage measuring means 6 measures the vertical transverse voltage V y in the traveling direction of the third of the spin-polarized current I Spin3.

このような論理演算ゲート３１は、第１のスピン偏極電流ＩSPIN１のキャリアのスピン偏極度Ｐ１及び第２のスピン偏極電流ＩSPIN２のキャリアのスピン偏極度Ｐ２を入力値、第３のスピン偏極電流ＩSPIN３のキャリアのスピン偏極度Ｐ３を出力値とする、２入力で１出力の擬似排他的論理演算ゲートを構成する。ここで、第１、第２及び第３の各スピン偏極度測定メータ１１Ａ、１１Ｂ及び１１Ｃは、チャネル領域δが非磁性体から構成されるため、アップ及びダウンスピンしたキャリアの双方を受け入れることが出来る。また、入力値であるスピン偏極度Ｐ１及びＰ２は、第１及び第２の各導電材料２Ａ及び２Ｂに外部磁場を印加して、または、第１及び第２の各導電材料２Ａ及び２Ｂの幅方向に電圧を印加してスピン偏極電流を注入し、キャリアのスピンを反転することで、任意に変えられる。 Such logical operation gate 31, the first spin-polarized current input value spin polarization P 2 of the carrier of the spin polarization P 1 and a second spin-polarized current I SPIN2 career I SPIN1, third A two-input and one-output pseudo-exclusive logic operation gate having an output value of the carrier spin polarization degree P 3 of the spin polarization current I SPIN3 is configured. Here, each of the first, second, and third spin polarization measurement meters 11A, 11B, and 11C can accept both the up-spinned and the down-spun carriers because the channel region δ is made of a nonmagnetic material. I can do it. In addition, the spin polarizations P 1 and P 2 that are input values are obtained by applying an external magnetic field to the first and second conductive materials 2A and 2B, or the first and second conductive materials 2A and 2B. By applying a voltage in the width direction, injecting a spin-polarized current, and reversing the spin of carriers, it can be changed arbitrarily.

すなわち、第１のメータ本体１２Ａ及び第２のメータ本体１２Ｂにそれぞれスピン偏極度Ｐ１及びＰ２が１００％の第１のスピン偏極電流ＩSPIN１及び第２のスピン偏極電流ＩSPIN２を注入すると、第３のメータ本体１２Ｃにはスピン偏極度Ｐ３が１００％の第３のスピン偏極電流ＩSPIN３が流れる。また、第１のメータ本体１２Ａ及び第２のメータ本体１２Ｂにそれぞれスピン偏極度Ｐ１が１００％の第１のスピン偏極電流ＩSPIN１及びスピン偏極度Ｐ２が−１００％の第２のスピン偏極電流ＩSPIN２を注入すると、第３のメータ本体１２Ｃにはスピン偏極度Ｐ３が０％の第３のスピン偏極電流ＩSPIN３が流れる。また、第１のメータ本体１２Ａ及び第２のメータ本体１２Ｂにそれぞれスピン偏極度Ｐ１が−１００％の第１のスピン偏極電流ＩSPIN１及びスピン偏極度Ｐ２が１００％の第２のスピン偏極電流ＩSPIN２を注入すると、第３のメータ本体１２Ｃにはスピン偏極度Ｐ３が０％の第３のスピン偏極電流ＩSPIN３が流れる。また、第１のメータ本体１２Ａ及び第２のメータ本体１２Ｂにそれぞれスピン偏極度Ｐ１及びＰ２が−１００％の第１のスピン偏極電流ＩSPIN１及び第２のスピン偏極電流ＩSPIN２を注入すると、第３のメータ本体１２Ｃにはスピン偏極度Ｐ３が−１００％の第３のスピン偏極電流ＩSPIN３が流れる。ここで、−１００％のスピン偏極度Ｐｓとは、全てのキャリアのスピンがダウンしている状態である。 In other words, injecting a first meter body 12A and the second respective to meter body 12B spin polarization P 1 and P 2 are the first 100% of the spin-polarized current I SPIN1 and second spin-polarized current I SPIN2 Then, spin polarization P 3 through the third spin-polarized current I Spin3 100% in the third meter body 12C. The first meter body 12A and the second respectively of the meter body 12B spin polarization P 1 is the first 100% of the spin-polarized current I SPIN1 and spin polarization P 2 -100% of the second spin injection of polarized current I SPIN2, the spin polarization P 3 through the third spin-polarized current I Spin3 0% in the third meter body 12C. The first meter body 12A and the second respective to meter body 12B spin polarization P 1 is the first -100% of the spin-polarized current I SPIN1 and spin polarization P 2 is 100% of the second spin injection of polarized current I SPIN2, the spin polarization P 3 through the third spin-polarized current I Spin3 0% in the third meter body 12C. Further, the first meter body 12A and the second respective to meter body 12B spin polarization P 1 and P 2 are a first -100% of the spin-polarized current I SPIN1 and second spin-polarized current I SPIN2 injecting, the spin polarization P 3 through the third spin-polarized current I Spin3 -100% in the third meter body 12C. Here, the spin polarization degree P s of −100% is a state in which the spins of all carriers are down.

このため、本実施の形態による論理演算ゲート３１では、第１のスピン偏極電流ＩSPIN１のキャリアのスピン偏極度Ｐ１及び第２のスピン偏極電流ＩSPIN２のキャリアのスピン偏極度Ｐ２を入力値、第３のスピン偏極電流ＩSPIN３のキャリアのスピン偏極度Ｐ３を出力値とすると、出力値Ｐ３及び一方の入力値Ｐ１またはＰ２が分かると、他方の入力値Ｐ２またはＰ１が一義的に推測される。ここで、各入力値Ｐ１、Ｐ２及び出力値Ｐ３は、第１〜第３の各メータ本体１２Ａ、１２Ｂ及び１２Ｃを流れる第１〜第３の各スピン偏極電流ＩSPIN１、ＩSPIN２及びＩSPIN３の進行方向に平行な縦方向電圧Ｖｘ及びこれに垂直な横方向電圧Ｖｙを電圧計Ｖ１Ａ、Ｖ１Ｂ及びＶ１Ｃ、並びにＶ２Ａ、Ｖ２Ｂ及びＶ２Ｃで測定し、縦抵抗率ρｘｘ及び横抵抗率ρｙｘを求めてスピン偏極度Ｐｓを算出することで、得られる。 Therefore, the logical operation gate 31 according to this embodiment, the spin polarization P 2 of the carrier of the first spin-polarized carrier of the spin-polarized current I SPIN1 extreme P 1 and a second spin-polarized current I SPIN2 input value, when an output value of the spin polarization P 3 of the carrier of the third spin-polarized current I Spin3, the output value P 3 and one input value P 1 or P 2 is known, the other input value P 2 or P 1 is uniquely deduced. Here, each input value P 1, P 2 and the output value P 3 is the first to third the meter body 12A, 12B and the first to flow through 12C third each spin polarized current I SPIN1, I SPIN2 and parallel longitudinal voltages V x and perpendicular thereto laterally voltage V y a voltmeter V 1A in the traveling direction of the I SPIN3, V 1B, and V 1C, and V 2A, measured by V 2B and V 2C, the vertical It is obtained by calculating the spin polarization P s by obtaining the resistivity ρ xx and the lateral resistivity ρ yx .

出力値Ｐ３及び一方の入力値Ｐ１またはＰ２から他方の入力値Ｐ２またはＰ１が一義的に推測されるこのような擬似排他的な論理関係は、図６（ａ）に示す真理値表にまとめられる。ここで、論理値「１」は１００％のスピン偏極度Ｐｓ、論理値「−１」は−１００％のスピン偏極度Ｐｓ、論理値「０」は０％のスピン偏極度Ｐｓに対応している。同図（ｂ）は、排他的論理和（ＸＯＲ）を演算する一般的な論理演算ゲートにおける入力値Ａ、Ｂ及び出力値Ｃ間の論理関係を表す真理値表である。この真理値表でも、出力値Ｃ及び一方の入力値ＡまたはＢから、他方の入力値ＢまたはＡが一義的に推測される。このため、同図（ａ）に演算論理を示す本実施の形態による論理演算ゲート３１の擬似ＸＯＲは、同図（ｂ）に演算論理を示す一般的なＸＯＲに類似する。従って、本実施の形態による論理演算ゲート３１により、擬似排他的な論理和を演算する擬似ＸＯＲゲートが提供される。 Such a pseudo-exclusive logical relationship in which the other input value P 2 or P 1 is uniquely estimated from the output value P 3 and one input value P 1 or P 2 is the truth shown in FIG. Summarized in a value table. Here, the logical value “1” is 100% spin polarization P s , the logical value “−1” is −100% spin polarization P s , and the logical value “0” is 0% spin polarization P s . It corresponds. FIG. 6B is a truth table showing a logical relationship between input values A and B and an output value C in a general logical operation gate that calculates an exclusive OR (XOR). Also in this truth table, the other input value B or A is uniquely estimated from the output value C and one input value A or B. For this reason, the pseudo XOR of the logic operation gate 31 according to the present embodiment whose operation logic is shown in FIG. 11A is similar to the general XOR whose operation logic is shown in FIG. Therefore, the logical operation gate 31 according to the present embodiment provides a pseudo XOR gate for calculating a pseudo exclusive OR.

図７は、一般的なＸＯＲ論理演算ゲート４１を５個のＰＮＰトランジスタ４２〜４６及び１個のＮＰＮトランジスタ４７で構成した一例を示す。入力値Ａをスイッチ４８、入力値Ｂをスイッチ４９で入力することで、出力端子５０に出力値Ｃが得られる。一般的なＸＯＲ論理演算ゲート４１はこのように６個のバイポーラ・トランジスタ４２〜４７を必要とする。１個当たりのこれらトランジスタ４２〜４７におけるＰＮ接合は２個であるから、ＸＯＲ論理演算ゲート４１には合計で１２個のＰＮ接合が必要とされる。これに対し、本実施の形態による擬似ＸＯＲ論理演算ゲート３１は、第１、第２及び第３の各非磁性導体３Ａ、３Ｂ及び３Ｃを一体成形することで、第１の導電材料２Ａと第１の非磁性導体３Ａとの接合、及び第２の導電材料２Ｂと第２の非磁性導体３Ｂとの接合の２個の接合で、極めて簡単に構成することが出来る。   FIG. 7 shows an example in which a general XOR logic operation gate 41 is composed of five PNP transistors 42 to 46 and one NPN transistor 47. By inputting the input value A with the switch 48 and the input value B with the switch 49, the output value C is obtained at the output terminal 50. A typical XOR logic operation gate 41 thus requires six bipolar transistors 42-47. Since each of these transistors 42 to 47 has two PN junctions, the XOR logic operation gate 41 requires a total of 12 PN junctions. On the other hand, the pseudo XOR logic operation gate 31 according to the present embodiment integrally forms the first, second, and third nonmagnetic conductors 3A, 3B, and 3C, so that the first conductive material 2A and the first conductive material 2A are integrated with each other. It can be configured very simply by joining the two nonmagnetic conductors 3A and the second conductive material 2B and the second nonmagnetic conductor 3B.

次に、上記の論理演算ゲート３１を用いた本発明による信号暗号化及び復号化方法の一実施の形態について説明する。   Next, an embodiment of a signal encryption / decryption method according to the present invention using the above-described logic operation gate 31 will be described.

本実施の形態の信号暗号化方法では、上記の論理演算ゲート３１における第１のメータ本体１２Ａ及び第２のメータ本体１２Ｂの一方に送信信号列、他方に乱数列を入力して、第３のメータ本体１２Ｃから出力される信号列を暗号列として送信する。例えば、第１のメータ本体１２Ａにおけるキャリアのスピン偏極度Ｐ１を図８（ａ）に示すスピン偏極信号列Ｐ１、第２のメータ本体１２Ｂにおけるキャリアのスピン偏極度Ｐ２を同図（ｂ）に示すスピン偏極乱数列Ｐ２として信号入力すると、第３のメータ本体１２Ｃのキャリアのスピン偏極度Ｐ３は、図６（ａ）に示す真理値表に従った同図（ｃ）に示す値となる。本実施の形態の信号暗号化方法では、同図（ｃ）に示すこの値の列を暗号化情報列Ｐ３として第３のメータ本体１２Ｃから出力し、情報通信における鍵暗号化を行う。 In the signal encryption method according to the present embodiment, a transmission signal sequence is input to one of the first meter body 12A and the second meter body 12B in the logic operation gate 31, and a random number sequence is input to the other. A signal string output from the meter main body 12C is transmitted as an encrypted string. For example, the spin-polarized signal sequence P 1 shown in FIG. 8 (a) the spin polarization P 1 of the carrier in the first meter body 12A, the spin polarization P 2 of the carrier of the second meter body 12B FIG ( When the signal input as a spin-polarized random number sequence P 2 shown in b), the spin polarization P 3 of the carrier of the third meter body 12C is drawing in accordance with the truth table shown in FIG. 6 (a) (c) It becomes the value shown in. The signal encryption method of the present embodiment, output from the third meter body 12C column of the value shown in (c) as encrypted information sequence P 3, performs key encryption in the information communication.

また、本実施の形態の信号復号化方法では、上記の論理演算ゲート３１の図６（ａ）に示す演算論理に基づいて、乱数列と受信した暗号列とから、送信信号列を復号する。例えば、図８（ｃ）に示す暗号化情報列Ｐ３を受信した場合には、送信時に用いた同図（ｂ）に示すスピン偏極乱数列Ｐ２と同じ同図（ｅ）に示すスピン偏極乱数列Ｐ２を用い、図６（ａ）に示す真理値表の論理に基づき、同図（ｆ）に示すスピン偏極信号列Ｐ１を復号化する。この復号化により、送信された同図（ａ）に示すスピン偏極信号列Ｐ１を得ることで、情報通信における鍵復号化を行う。 Further, in the signal decoding method according to the present embodiment, the transmission signal sequence is decoded from the random number sequence and the received encrypted sequence based on the operation logic shown in FIG. For example, the spin shown in the case of receiving the encrypted information sequence P 3 shown in FIG. 8 (c), the same figure as the spin-polarized random number sequence P 2 shown in (b) was used at the time of transmission (e) using polarized random number sequence P 2, based on the logic of the truth table shown in FIG. 6 (a), decodes the spin-polarized signal sequence P 1 shown in FIG. (f). By this decryption, the transmitted spin-polarized signal sequence P 1 shown in FIG. 5A is obtained, and key decryption in information communication is performed.

このような本実施の形態の信号暗号化及び復号化方法によれば、上記のように、第１のメータ本体１２Ａに入力される送信信号列Ｐ１と第２のメータ本体１２Ｂに入力される乱数列Ｐ２とは、論理演算ゲート３１によって図６（ａ）に示す擬似排他的論理和がとられ、その論理演算結果が暗号列Ｐ３として第３のメータ本体１２Ｃから出力され、送信される。論理演算ゲート３１は、出力値である暗号列Ｐ３及び一方の入力値である乱数列Ｐ２から他方の入力値である入力信号列Ｐ１が一義的に推測されるので、受信側では、乱数列Ｐ２と受信した暗号列Ｐ３とから、論理演算ゲート３１の演算論理に基づいて、送信した信号列Ｐ１を復号化することが出来る。 According to the signal encryption and decryption method of the present embodiment, as described above, it is input and the transmission signal sequence P 1 that is input to the first meter body 12A to the second meter body 12B the random number sequence P 2, pseudo XOR shown in FIG. 6 (a) is taken by the logical operation gate 31, the logical operation result is outputted from the third meter body 12C as the encryption sequence P 3, it is transmitted The Since the logical operation gate 31 uniquely estimates the input signal string P 1 as the other input value from the encrypted string P 3 as the output value and the random number string P 2 as one input value, from the random number sequence P 2 and received cipher sequence P 3 Prefecture, on the basis of the calculation logic of logic operations gates 31, it is possible to decode the transmitted signal sequence P 1.

このため、上記の擬似ＸＯＲ論理演算ゲート３１を用いることで、送信信号列Ｐ１を暗号列Ｐ３に暗号化することが出来、暗号列Ｐ３を送信信号列Ｐ１に復号化することが出来る信号暗号化及び復号化方法が提供される。 Therefore, by using the pseudo XOR logic operation gate 31 described above, the transmission signal sequence P 1 can be encrypted into the encrypted sequence P 3 , and the encrypted sequence P 3 can be decrypted into the transmission signal sequence P 1. Possible signal encryption and decryption methods are provided.

ＸＯＲ論理演算ゲート４１は、各種ＴＴＬを始め、鍵暗号通信における情報の暗号化及び復号化技術に必須の論理ゲートである。このため、本発明によるスピン偏極度ＰＳを入出力とする上述した擬似ＸＯＲ論理演算ゲート３１は、これらディジタル回路における省電力化と高度集積化に格段の進歩をもたらす。 The XOR logic operation gate 41 is a logic gate essential for information encryption and decryption techniques in key encryption communication including various TTLs. Therefore, the pseudo-XOR logic operation gates 31 described above to the spin polarization P S of the present invention and input-output leads to a great improvement in the power saving and high integration in these digital circuits.

１…伝導電子
１α…スピンアップした伝導電子
１β…スピンダウンした伝導電子
２…被測定材料
２ａ…スピン偏極源
２Ａ、２Ｂ…導電材料
３…非磁性導体
３ａ、３Ａ、３Ｂ、３Ｃ…非磁性導体
１１…スピン偏極度測定メータ
１２、１２Ａ、１２Ｂ、１２Ｃ…メータ本体
２１…較正器
３１…論理演算ゲート
Ｉ…電流
δ…チャネル領域
ｆＳＯＩ…スピン軌道相互作用力
ｆＨａｌｌ…ホール電気力
ＥＨ…ホール電場
ｍ…スピン磁気モーメント
Ｉｓｐｉｎ…スピン偏極電流
Ｖ１、Ｖ２…電圧計 DESCRIPTION OF SYMBOLS 1 ... Conduction electron 1 (alpha) ... Spin-up conduction electron 1 (beta) ... Spin-down conduction electron 2 ... Material to be measured 2a ... Spin polarization source 2A, 2B ... Conductive material 3 ... Nonmagnetic conductor 3a, 3A, 3B, 3C ... Nonmagnetic Conductor 11 ... Spin polarization measurement meter 12, 12A, 12B, 12C ... Meter body 21 ... Calibrator 31 ... Logic operation gate I ... Current δ ... Channel region f SOI ... Spin orbit interaction force f Hall ... Hall electric force E H ... Hall electric field m ... Spin magnetic moment I spin ... Spin polarized current V 1 , V 2 ... Voltmeter

Claims (6)

導電性を有する被測定材料に接合された非磁性導体に前記被測定材料から注入されたスピン偏極電流の進行方向に沿う縦方向の縦抵抗を測定し、電流進行方向に直交する横方向における前記非磁性導体の横抵抗を測定し、測定した前記縦抵抗及び前記横抵抗から前記非磁性導体の横抵抗率の縦抵抗率に対する縦横抵抗率比を求め、前記縦横抵抗率比と前記非磁性導体におけるキャリアのスピン偏極度とが、前記非磁性導体におけるキャリアの移動度とスピン軌道相互作用の強さとの積を比例係数とする比例関係にあることに基づいて、前記縦横抵抗率比から前記被測定材料のスピン偏極度の相対値を評価するスピン偏極度測定方法。   Measure the longitudinal longitudinal resistance along the traveling direction of the spin-polarized current injected from the measured material into the non-magnetic conductor joined to the measured material having conductivity, and in the lateral direction perpendicular to the traveling direction of the current The transverse resistance of the nonmagnetic conductor is measured, and the longitudinal and lateral resistivity ratio of the transverse resistivity of the nonmagnetic conductor to the longitudinal resistivity is obtained from the measured longitudinal resistance and the transverse resistance, and the longitudinal and lateral resistivity ratio and the nonmagnetic property are obtained. Based on the fact that the spin polarization degree of the carrier in the conductor has a proportional relationship in which the product of the mobility of the carrier in the nonmagnetic conductor and the strength of the spin-orbit interaction is a proportional coefficient, A spin polarization measurement method for evaluating the relative value of the spin polarization of a material to be measured. スピン偏極度が０％のときの前記縦抵抗率の、スピン偏極度が１００％のときの前記縦抵抗率に対する比から１を減算した減算値で、或るスピン偏極度における前記縦横抵抗率比の二乗値を割った値がそのスピン偏極度の二乗値に等しい関係に基づいて、前記被測定材料のスピン偏極度の絶対値を評価することを特徴とする請求項１に記載のスピン偏極度測定方法。   A ratio obtained by subtracting 1 from the ratio of the longitudinal resistivity when the spin polarization is 0% to the longitudinal resistivity when the spin polarization is 100%, and the ratio of the longitudinal and lateral resistivity at a certain spin polarization. 2. The spin polarization degree according to claim 1, wherein the absolute value of the spin polarization degree of the material to be measured is evaluated based on a relationship in which a value obtained by dividing the square value of is equal to a square value of the spin polarization degree. Measuring method. 前記被測定材料に非磁性導体が接合されて構成される素子の両端に電圧を印加して前記被測定材料から前記非磁性導体にスピン偏極電流を注入し、前記非磁性導体における前記スピン偏極電流の進行方向に平行な縦方向電圧、及び前記スピン偏極電流の進行方向に垂直な横方向電圧を測定し、前記縦方向電圧を前記スピン偏極電流の電流値で割った値を前記縦抵抗、前記横方向電圧を前記スピン偏極電流の電流値で割った値を前記横抵抗とすることを特徴とする請求項１または請求項２に記載のスピン偏極度測定方法。   A voltage is applied to both ends of an element formed by joining a nonmagnetic conductor to the material to be measured to inject a spin-polarized current from the material to be measured into the nonmagnetic conductor, and the spin polarization in the nonmagnetic conductor A longitudinal voltage parallel to the traveling direction of the polar current and a lateral voltage perpendicular to the traveling direction of the spin-polarized current are measured, and the value obtained by dividing the longitudinal voltage by the current value of the spin-polarized current is The spin polarization measurement method according to claim 1 or 2, wherein a value obtained by dividing a longitudinal resistance and the lateral voltage by a current value of the spin polarization current is used as the transverse resistance. 導電性を有する被測定材料に非磁性導体が接合されたメータ本体と、前記メータ本体の両端に電圧を印加して前記被測定材料から前記非磁性導体に注入されたスピン偏極電流の進行方向に平行な縦方向電圧を測定する第１の電圧測定手段と、前記スピン偏極電流の進行方向に垂直な横方向電圧を測定する第２の電圧測定手段とから構成されるスピン偏極度測定メータ。   A meter body in which a nonmagnetic conductor is bonded to a material to be measured having conductivity, and a traveling direction of a spin-polarized current injected from the material to be measured into the nonmagnetic conductor by applying a voltage to both ends of the meter body A spin polarization degree meter comprising: a first voltage measuring means for measuring a longitudinal voltage parallel to the first voltage measuring means; and a second voltage measuring means for measuring a lateral voltage perpendicular to the traveling direction of the spin polarized current. . 導電性を有する第１の導電材料に第１の非磁性導体が接合された第１のメータ本体、第１の前記メータ本体の両端に電圧を印加して第１の前記導電材料から第１の前記非磁性導体に注入された第１のスピン偏極電流の進行方向に平行な縦方向電圧を測定する第１の電圧測定手段、及び、第１の前記スピン偏極電流の進行方向に垂直な横方向電圧を測定する第２の電圧測定手段から構成される第１のスピン偏極度測定メータと、
導電性を有する第２の導電材料に第２の非磁性導体が接合された第２のメータ本体、第２の前記メータ本体の両端に電圧を印加して第２の前記導電材料から第２の前記非磁性導体に注入された第２のスピン偏極電流の進行方向に平行な縦方向電圧を測定する第３の電圧測定手段、及び、第２の前記スピン偏極電流の進行方向に垂直な横方向電圧を測定する第４の電圧測定手段から構成される第２のスピン偏極度測定メータと、
第３の非磁性導体からなる第３のメータ本体、第１の前記非磁性導体及び第２の前記非磁性導体から第３の前記非磁性導体に流入する第１の前記スピン偏極電流及び第２の前記スピン偏極電流が合成して形成される第３のスピン偏極電流の進行方向に平行な縦方向電圧を測定する第５の電圧測定手段、及び、第３の前記スピン偏極電流の進行方向に垂直な横方向電圧を測定する第６の電圧測定手段から構成される第３のスピン偏極度測定メータと
を備えて構成され、
第１の前記スピン偏極電流のキャリアのスピン偏極度及び第２の前記スピン偏極電流のキャリアのスピン偏極度を入力値、第３の前記スピン偏極電流のキャリアのスピン偏極度を出力値とする論理演算ゲート。 A first meter body in which a first nonmagnetic conductor is joined to a first conductive material having conductivity, a voltage is applied to both ends of the first meter body, and the first conductive material is used to First voltage measuring means for measuring a longitudinal voltage parallel to the traveling direction of the first spin-polarized current injected into the nonmagnetic conductor, and perpendicular to the traveling direction of the first spin-polarized current A first spin polarization measuring meter comprising second voltage measuring means for measuring a lateral voltage;
A second meter body in which a second non-magnetic conductor is joined to a second conductive material having conductivity; a voltage is applied to both ends of the second meter body to apply a second from the second conductive material; Third voltage measuring means for measuring a longitudinal voltage parallel to the traveling direction of the second spin-polarized current injected into the non-magnetic conductor, and perpendicular to the traveling direction of the second spin-polarized current A second spin polarization measuring meter comprising fourth voltage measuring means for measuring a lateral voltage;
A third meter body composed of a third nonmagnetic conductor, a first spin-polarized current flowing into the third nonmagnetic conductor from the first nonmagnetic conductor and the second nonmagnetic conductor; 5th voltage measuring means for measuring a longitudinal voltage parallel to the traveling direction of the third spin-polarized current formed by combining the two spin-polarized currents, and the third spin-polarized current A third spin polarization measuring meter comprising sixth voltage measuring means for measuring a lateral voltage perpendicular to the traveling direction of
The spin polarization of the carrier of the first spin-polarized current and the spin polarization of the carrier of the second spin-polarized current are input values, and the spin polarization of the carrier of the third spin-polarized current is output. Logical operation gate. 第１の前記メータ本体及び第２の前記メータ本体の一方に送信信号列、他方に乱数列を入力して第３の前記メータ本体から出力される信号列を暗号列として送信し、前記論理演算ゲートの演算論理に基づいて前記乱数列と受信した前記暗号列とから前記送信信号列を復号する、請求項５に記載の論理演算ゲートを用いた信号暗号化及び復号化方法。   A transmission signal sequence is input to one of the first meter body and the second meter body, a random number sequence is input to the other, and a signal sequence output from the third meter body is transmitted as an encryption sequence, and the logical operation is performed. 6. The signal encryption and decryption method using a logic operation gate according to claim 5, wherein the transmission signal sequence is decrypted from the random number sequence and the received cipher sequence based on a gate operation logic.
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JPH1056219A (en) * 1996-05-06 1998-02-24 Mark B Johnson Hall effect element and its operating method
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