中国物理B ›› 2011, Vol. 20 ›› Issue (7): 77302-077302.doi: 10.1088/1674-1056/20/7/077302

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Spin current and its heat effect in a multichannel quantum wire with Rashba spin–orbit coupling

宋占锋, 王亚东, 邵慧彬, 孙志刚   

  1. Zhangjiakou Vocational and Technical College, Zhangjiakou 075000, China
  • 收稿日期:2010-11-07 修回日期:2010-12-08 出版日期:2011-07-15 发布日期:2011-07-15

Spin current and its heat effect in a multichannel quantum wire with Rashba spin–orbit coupling

Song Zhan-Feng(宋占锋), Wang Ya-Dong(王亚东), Shao Hui-Bin(邵慧彬), and Sun Zhi-Gang(孙志刚)   

  1. Zhangjiakou Vocational and Technical College, Zhangjiakou 075000, China
  • Received:2010-11-07 Revised:2010-12-08 Online:2011-07-15 Published:2011-07-15

摘要: Using the perturbation method, we theoretically study the spin current and its heat effect in a multichannel quantum wire with Rashba spin—orbit coupling. The heat generated by the spin current is calculated. With the increase of the width of the quantum wire, the spin current and the heat generated both exhibit period oscillations with equal amplitudes. When the quantum-channel number is doubled, the oscillation periods of the spin current and of the heat generated both decrease by a factor of 2. For the spin current js,xy, the amplitude increases with the decrease of the quantum channel; while the amplitude of the spin current js,yx remains the same. Therefore we conclude that the effect of the quantum-channel number on the spin current js,xy is greater than that on the spin current js,yx. The strength of the Rashba spin—orbit coupling is tunable by the gate voltage, and the gate voltage can be varied experimentally, which implies a new method of detecting the spin current. In addition, we can control the amplitude and the oscillation period of the spin current by controlling the number of the quantum channels. All these characteristics of the spin current will be very important for detecting and controlling the spin current, and especially for designing new spintronic devices in the future.

Abstract: Using the perturbation method, we theoretically study the spin current and its heat effect in a multichannel quantum wire with Rashba spin–orbit coupling. The heat generated by the spin current is calculated. With the increase of the width of the quantum wire, the spin current and the heat generated both exhibit period oscillations with equal amplitudes. When the quantum-channel number is doubled, the oscillation periods of the spin current and of the heat generated both decrease by a factor of 2. For the spin current js,xy, the amplitude increases with the decrease of the quantum channel; while the amplitude of the spin current js,yx remains the same. Therefore we conclude that the effect of the quantum-channel number on the spin current js,xy is greater than that on the spin current js,yx. The strength of the Rashba spin—orbit coupling is tunable by the gate voltage, and the gate voltage can be varied experimentally, which implies a new method of detecting the spin current. In addition, we can control the amplitude and the oscillation period of the spin current by controlling the number of the quantum channels. All these characteristics of the spin current will be very important for detecting and controlling the spin current, and especially for designing new spintronic devices in the future.

Key words: multichannel quantum wire, Rashba spin–orbit coupling, spin current, heat produced by spin current

中图分类号:  (Persistent currents)

  • 73.23.Ra
71.70.Ej (Spin-orbit coupling, Zeeman and Stark splitting, Jahn-Teller effect) 72.25.Dc (Spin polarized transport in semiconductors) 73.63.Nm (Quantum wires)