Beiranvand Razieh, Hamzehpour Hossein
Physics Group, Department of Basic Science, Ayatollah Boroujerdi University, Boroujerd, Iran.
Department of Physics, K.N. Toosi University of Technology, Tehran, 15875-4416, Iran.
Sci Rep. 2020 Feb 6;10(1):2009. doi: 10.1038/s41598-020-58799-6.
We theoretically investigate the crossed spin conductance (CSC) of a graphene-based heterostructure consists of ferromagnet, Rashba spin-orbit and superconductor regions. Using Dirac Bogoliubov-de Gennes formalism in the ballistic regime, we show that in the presence of Rashba spin-orbit coupling there are an anomalous crossed Andreev reection and spin-ipped co-tunneling in the process of quantum transport. We demonstrate that the CSC can be reversed with respect to charge conductance by tuning the Rashba spin-orbit coupling which experimentally can be adjusted by the applied perpendicular electric field on the graphene sheet. This feature in addition to a long spin relaxation time of Dirac fermions in graphene proposes designing a device with a non-local spin switch which is crucial for spintronics circuits.
我们从理论上研究了一种由铁磁体、Rashba 自旋轨道和超导体区域组成的基于石墨烯的异质结构的交叉自旋电导（CSC）。在弹道区域使用狄拉克 Bogoliubov - de Gennes 形式理论，我们表明，在存在 Rashba 自旋轨道耦合的情况下，量子输运过程中存在反常交叉安德烈夫反射和自旋翻转共隧穿。我们证明，通过调节 Rashba 自旋轨道耦合，CSC 可以相对于电荷电导反转，而在实验中，这可以通过在石墨烯片上施加垂直电场来调节。除了石墨烯中狄拉克费米子的长自旋弛豫时间外，这一特性还为设计一种对自旋电子学电路至关重要的非局部自旋开关器件提供了思路。
