嵌有两个量子点的三终端量子环中的横向自旋流
从理论上研究了一个上臂与下臂各嵌有一个量子点的三终端三臂量子环中的自旋极化的电子输运性质.考虑了两个量子点中的库仑互作用并假设在某一个环臂中存在Rashba自旋轨道耦合作用.利用非平衡态格林函数方法,发现不需要借助任何磁场与磁性物质Rashba自旋轨道耦合作用导致的量子干涉效应就可以从器件中驱动出一个自旋流.适当调节外加偏压、Rashba自旋轨道耦合作用强度以及量子点能级等系统参数时器件中甚至还可以产生完全自旋极化电流或纯自旋流.另外,还讨论了系统参数对自旋流大小、符号、自旋极化度以及峰值的影响....
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| Published in | 红外与毫米波学报 Vol. 33; no. 4; pp. 349 - 354 |
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| Main Author | |
| Format | Journal Article |
| Language | Chinese |
| Published |
淮阴工学院数理学院,江苏淮安,223003%暨南大学物理系与思源实验室,广东广州,510632
2014
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| Subjects | |
| Online Access | Get full text |
| ISSN | 1001-9014 |
| DOI | 10.3724/SP.J.1010.2014.00349 |
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| Summary: | 从理论上研究了一个上臂与下臂各嵌有一个量子点的三终端三臂量子环中的自旋极化的电子输运性质.考虑了两个量子点中的库仑互作用并假设在某一个环臂中存在Rashba自旋轨道耦合作用.利用非平衡态格林函数方法,发现不需要借助任何磁场与磁性物质Rashba自旋轨道耦合作用导致的量子干涉效应就可以从器件中驱动出一个自旋流.适当调节外加偏压、Rashba自旋轨道耦合作用强度以及量子点能级等系统参数时器件中甚至还可以产生完全自旋极化电流或纯自旋流.另外,还讨论了系统参数对自旋流大小、符号、自旋极化度以及峰值的影响. |
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| Bibliography: | quantum ring, quantum dot, spin current, nonequilibrium Green＇ s function The spin-polarized electron transport through a three-terminal three-arm ring with two quantum dots sepa- rately embedded in the upper and lower arms were theoretically studied. The intradot Coulomb interaction on the two dots and the Rashba spin-orbit interaction inside one arm of the ring were taken into account. With the aid of the non- equilibrium Green＇s function method, we find that even without using any magnetic factors a Rashba induced spin in- terference effect can drive a spin-polarlzed current out of the device. By properly tuning the system parameters such as the applied external voltages, the Rashba interaction strength and the dot levels, not only a fully spin-polarized current but also a pure spin current can be obtained. Moreover,the effects of the system parameters on the magnitude, sign, spin-polarization and resonant peaks of the spin-polarized current were also discussed. 31-1577/TN LIANG Feng, GU Yu （ 1. Department of |
| ISSN: | 1001-9014 |
| DOI: | 10.3724/SP.J.1010.2014.00349 |