| 摘要: |
| 近年来,石墨烯中电子的自旋相关输运引起了越来越多的关注.本论文应用转移矩阵的方法讨论了石墨烯中具有单个界面或者两个界面的结构中,受到自旋-轨道耦合作用和电势的共同影响下自旋相关的输运性质.对于单个界面结构,由于自旋-轨道耦合作用导致能级产生劈裂,在固定的入射能量下,电子在自旋-轨道耦合区域产生两种传播模式.在自旋-轨道耦合区域加了电势后,透射几率和模式临界角都会受到较大的影响.对于两个界面结构,粒子的透射几率不仅与入射角有关,还与自旋-轨道耦合区域的宽度和自旋进动长度有关,而电势对同自旋方向的传输几率以及自旋反转的几率都有影响,适当地选取系统的参数和电势的大小,可以控制出射的电子自旋方向,实验上可以用来设计自旋反转器或者或者自旋控制器. |
| 关键词: 石墨烯,传输矩阵,自旋轨道耦合,透射概率 |
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| Spin Polarization Property with the Common Modulation of the Spin-Orbit Coupling and Electric Potential |
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ZHAO Zhiyun1, MU Pingping2
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| (1.College of Science, Nan tong University, Nan tong 226019, China;2.School of Teacher Eduation, Nanjing Normal University, 210024, China) |
| Abstract: |
| Recently, spin-dependent transport in graphene has attracted more and more attention. In this paper, considering the influence of the electric potential and different spin orbit couplings, we apply the transfer-matrix approach to discuss the spin-dependent transport in a structure with a single or double interface between an ormal
region and a spin-orbit coupling (SOC) region. For a single interface structure, the energy spectrum splits due to the existence of SOC. When a particle incidents to the surface at the fixed energy, the incident wave in the SOC region turns into two modes propagating along two distinct directions. When we add an electri cpotential to the SOC region, both the critical angle and transmission probabilities change. For a double interface, the transmission probability of particles depends not only on the incident angle,but also on the width of the spin-orbit coupling region and the spin precession length. The electric potential has an effect on the transmission probability of the same spin direction and the contrary spin direction. Proper selection of the parameters and the electric potential of the system can control the spin direction of the emitted electron. It can be used to design the spin reversor or spin controller in experiments. |
| Key words: Graphene, Transfermatrix,Spin-orbit coupling, Transmission probability |
