中国物理B ›› 2021, Vol. 30 ›› Issue (5): 57201-057201.doi: 10.1088/1674-1056/abcf35

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Tunable valley filter efficiency by spin-orbit coupling in silicene nanoconstrictions

Yi-Jian Shi(施一剑), Yuan-Chun Wang(王园春), and Peng-Jun Wang(汪鹏君)   

  1. College of Electrical and Electronic Engineering, Wenzhou University, Wenzhou 325035, China
  • 收稿日期:2020-07-07 修回日期:2020-11-12 接受日期:2020-12-01 出版日期:2021-05-14 发布日期:2021-05-14
  • 通讯作者: Peng-Jun Wang E-mail:wangpengjun@wzu.edu.cn
  • 基金资助:
    Project supported by the Natural Science Foundation of Zhejiang Province, China (Grant No. LQ17A040001), the National Natural Science Foundation of China (Grant Nos. 61874078, 11647046, and 61904125), the National Key Research and Development Program of China (Grant No. 2018YFB2202100), and the Science and Technology Planning Project of Wenzhou City (Grant No. G20180012).

Tunable valley filter efficiency by spin-orbit coupling in silicene nanoconstrictions

Yi-Jian Shi(施一剑), Yuan-Chun Wang(王园春), and Peng-Jun Wang(汪鹏君)   

  1. College of Electrical and Electronic Engineering, Wenzhou University, Wenzhou 325035, China
  • Received:2020-07-07 Revised:2020-11-12 Accepted:2020-12-01 Online:2021-05-14 Published:2021-05-14
  • Contact: Peng-Jun Wang E-mail:wangpengjun@wzu.edu.cn
  • Supported by:
    Project supported by the Natural Science Foundation of Zhejiang Province, China (Grant No. LQ17A040001), the National Natural Science Foundation of China (Grant Nos. 61874078, 11647046, and 61904125), the National Key Research and Development Program of China (Grant No. 2018YFB2202100), and the Science and Technology Planning Project of Wenzhou City (Grant No. G20180012).

摘要: Valley filter is a promising device for producing valley polarized current in graphene-like two-dimensional honeycomb lattice materials. The relatively large spin-orbit coupling in silicene contributes to remarkable quantum spin Hall effect, which leads to distinctive valley-dependent transport properties compared with intrinsic graphene. In this paper, quantized conductance and valley polarization in silicene nanoconstrictions are theoretically investigated in quantum spin-Hall insulator phase. Nearly perfect valley filter effect is found by aligning the gate voltage in the central constriction region. However, the valley polarization plateaus are shifted with the increase of spin-orbit coupling strength, accompanied by smooth variation of polarization reversal. Our findings provide new strategies to control the valley polarization in valleytronic devices.

关键词: valley polarization, spin-orbit coupling, quantization, silicene

Abstract: Valley filter is a promising device for producing valley polarized current in graphene-like two-dimensional honeycomb lattice materials. The relatively large spin-orbit coupling in silicene contributes to remarkable quantum spin Hall effect, which leads to distinctive valley-dependent transport properties compared with intrinsic graphene. In this paper, quantized conductance and valley polarization in silicene nanoconstrictions are theoretically investigated in quantum spin-Hall insulator phase. Nearly perfect valley filter effect is found by aligning the gate voltage in the central constriction region. However, the valley polarization plateaus are shifted with the increase of spin-orbit coupling strength, accompanied by smooth variation of polarization reversal. Our findings provide new strategies to control the valley polarization in valleytronic devices.

Key words: valley polarization, spin-orbit coupling, quantization, silicene

中图分类号:  (Electronic transport in graphene)

  • 72.80.Vp
73.22.Pr (Electronic structure of graphene) 71.70.Ej (Spin-orbit coupling, Zeeman and Stark splitting, Jahn-Teller effect) 73.23.-b (Electronic transport in mesoscopic systems)