中国物理B ›› 2013, Vol. 22 ›› Issue (4): 47302-047302.doi: 10.1088/1674-1056/22/4/047302

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

Pure spin polarized transport based on Rashba spin–orbit interaction through the Aharonov–Bohm interferometer embodied four-quantum-dot ring

吴丽君a, 韩宇b   

  1. a School of Science, Shenyang Ligong University, Shenyang 110159, China;
    b Department of Physics, Liaoning University, Shenyang 110036, China
  • 收稿日期:2012-08-22 修回日期:2012-10-09 出版日期:2013-03-01 发布日期:2013-03-01
  • 基金资助:
    Project supported by the Natural Science Foundation of Liaoning Province, China (Grant No. 201202085), the National Natural Science Foundation of China (Grant No. 11004138), the Excellent Young Scientists Fund of Liaoning Provence, China (Grant No. LJQ2011020), and the Young Scientists Fund of Shenyang Ligong University (Grant No. 2011QN-04-11).

Pure spin polarized transport based on Rashba spin–orbit interaction through the Aharonov–Bohm interferometer embodied four-quantum-dot ring

Wu Li-Jun (吴丽君)a, Han Yu (韩宇)b   

  1. a School of Science, Shenyang Ligong University, Shenyang 110159, China;
    b Department of Physics, Liaoning University, Shenyang 110036, China
  • Received:2012-08-22 Revised:2012-10-09 Online:2013-03-01 Published:2013-03-01
  • Contact: Wu Li-Jun, Han Yu E-mail:wulijun20070915@163.com; hanyu@lnu.edu.cn
  • Supported by:
    Project supported by the Natural Science Foundation of Liaoning Province, China (Grant No. 201202085), the National Natural Science Foundation of China (Grant No. 11004138), the Excellent Young Scientists Fund of Liaoning Provence, China (Grant No. LJQ2011020), and the Young Scientists Fund of Shenyang Ligong University (Grant No. 2011QN-04-11).

摘要: The spin-polarized linear conductance spectrum and current-voltage characteristics in a four-quantum-dot ring embodied into Aharonov-Bohm (AB) interferometer are investigated theoretically by considering a local Rashba spin-orbit interaction. It shows that the spin-polarized linear conductance and the corresponding spin polarization each are a function of magnetic flux phase at zero bias voltage with a period of 2π, and that Hubbard U cannot influence the electron transport properties in this case. When adjusting appropriately structural parameter of inter-dot coupling and dot-lead coupling strength, the electronic spin polarization can reach a maximum value. Furthermore, by adjusting the bias voltages applied to the leads, the spin-up and spin-down currents move in opposite directions and pure spin current exists in the configuration space in appropriate situation. Based on the numerical results, such a model can be applied to the design of spin filter device.

关键词: quantum dot ring, Rashba spin-orbit interaction, spin-polarized transport, "bound states in the continuum", phenomena, bias voltage, Aharonov-Bohm interferometer

Abstract: The spin-polarized linear conductance spectrum and current–voltage characteristics in a four-quantum-dot ring embodied into Aharonov–Bohm (AB) interferometer are investigated theoretically by considering a local Rashba spin–orbit interaction. It shows that the spin-polarized linear conductance and the corresponding spin polarization each are a function of magnetic flux phase at zero bias voltage with a period of 2π, and that Hubbard U cannot influence the electron transport properties in this case. When adjusting appropriately structural parameter of inter-dot coupling and dot-lead coupling strength, the electronic spin polarization can reach a maximum value. Furthermore, by adjusting the bias voltages applied to the leads, the spin-up and spin-down currents move in opposite directions and pure spin current exists in the configuration space in appropriate situation. Based on the numerical results, such a model can be applied to the design of spin filter device.

Key words: quantum dot ring, Rashba spin–orbit interaction, spin-polarized transport, "bound states in the continuum", phenomena, bias voltage, Aharonov–Bohm interferometer

中图分类号:  (Electronic transport in mesoscopic systems)

  • 73.23.-b
73.63.-b (Electronic transport in nanoscale materials and structures)