Shen Jinhui, Feng Zheng, Xu Pengchao, Hou Dazhi, Gao Yang, Jin Xiaofeng
State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China.
Collaborative Innovation Center of Advanced Microstructures, Fudan University, Shanghai 200433, China.
Phys Rev Lett. 2021 May 14;126(19):197201. doi: 10.1103/PhysRevLett.126.197201.
The spin-to-charge conversion of the Ag/Bi interface is studied in a device in which a spin current can be injected from either side selectively. The charge voltages generated by the two counterpropagating spin currents show opposite signs, that is consistent with the inverse spin Hall effect rather than the well-accepted inverse Rashba-Eldestein effect in the Ag/Bi bilayer. Femtosecond laser is further employed to generate the spin-current-induced terahertz signal in a Ag/Bi bilayer, which shows no evidence for the inverse Rashba-Eldestein effect, either. This work provides a clear-cut method to identify the spin-to-charge mechanism in a Rashba electronic state and delivers new understanding for the relevant spin-transport phenomena.
在一个能够从两侧选择性注入自旋电流的器件中，研究了Ag/Bi界面的自旋到电荷的转换。由两个反向传播的自旋电流产生的电荷电压显示出相反的符号，这与逆自旋霍尔效应一致，而不是Ag/Bi双层中广泛接受的逆Rashba-Eldestein效应。进一步利用飞秒激光在Ag/Bi双层中产生自旋电流诱导的太赫兹信号，这也没有显示出逆Rashba-Eldestein效应的证据。这项工作提供了一种明确的方法来识别Rashba电子态中的自旋到电荷机制，并为相关的自旋输运现象提供了新的理解。
