中国物理B ›› 2017, Vol. 26 ›› Issue (5): 57303-057303.doi: 10.1088/1674-1056/26/5/057303

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

Generation of Fabry-Pérot oscillations and Dirac state in two-dimensional topological insulators by gate voltage

Bin Xu(徐斌), Rao Li(李饶), Hua-Hua Fu(傅华华)   

  1. 1 Department of Mathematics and Information Sciences, North China university of Water Resources and Electric Power, Zhengzhou 450011, China;
    2 Henan Mechanical and Electrical Vocational College, Zhengzhou 451191, China;
    3 School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
  • 收稿日期:2016-12-05 修回日期:2017-02-05 出版日期:2017-05-05 发布日期:2017-05-05
  • 通讯作者: Bin Xu E-mail:hnsqxb@163.com
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. U1404108, 11104072, and 10947162) and Henan Foundation and Frontier Technology Research Program of China (Grant No. 162300410056).

Generation of Fabry-Pérot oscillations and Dirac state in two-dimensional topological insulators by gate voltage

Bin Xu(徐斌)1, Rao Li(李饶)2, Hua-Hua Fu(傅华华)3   

  1. 1 Department of Mathematics and Information Sciences, North China university of Water Resources and Electric Power, Zhengzhou 450011, China;
    2 Henan Mechanical and Electrical Vocational College, Zhengzhou 451191, China;
    3 School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
  • Received:2016-12-05 Revised:2017-02-05 Online:2017-05-05 Published:2017-05-05
  • Contact: Bin Xu E-mail:hnsqxb@163.com
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. U1404108, 11104072, and 10947162) and Henan Foundation and Frontier Technology Research Program of China (Grant No. 162300410056).

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摘要： We investigate electron transport through HgTe ribbons embedded by strip-shape gate voltage through using a non-equilibrium Green function technique. The numerical calculations show that as the gate voltage is increased, an edge-related state in the valence band structure of the system shifts upwards, then hangs inside the band gap and merges into the conduction band finally. It is interesting that as the gate voltage is increased continuously, another edge-related state in the valence band also shifts upwards in the small-k region and contacts the previous one to form a Dirac cone in the band structure. Meanwhile in this process, the conductance spectrum displays as multiple resonance peaks characterized by some strong antiresonance valleys in the band gap, then behaves as Fabry-Pérot oscillations and finally develops into a nearly perfect quantum plateau with a value of 2e2/h. These results give a physical picture to understand the formation process of the Dirac state driven by the gate voltage and provide a route to achieving particular quantum oscillations of the electronic transport in nanodevices.

关键词: Fabry-Pé, rot oscillations, Diarc cone, electronic transport, HgTe quantum well

Abstract: We investigate electron transport through HgTe ribbons embedded by strip-shape gate voltage through using a non-equilibrium Green function technique. The numerical calculations show that as the gate voltage is increased, an edge-related state in the valence band structure of the system shifts upwards, then hangs inside the band gap and merges into the conduction band finally. It is interesting that as the gate voltage is increased continuously, another edge-related state in the valence band also shifts upwards in the small-k region and contacts the previous one to form a Dirac cone in the band structure. Meanwhile in this process, the conductance spectrum displays as multiple resonance peaks characterized by some strong antiresonance valleys in the band gap, then behaves as Fabry-Pérot oscillations and finally develops into a nearly perfect quantum plateau with a value of 2e2/h. These results give a physical picture to understand the formation process of the Dirac state driven by the gate voltage and provide a route to achieving particular quantum oscillations of the electronic transport in nanodevices.

Key words: Fabry-Pérot oscillations, Diarc cone, electronic transport, HgTe quantum well

中图分类号:  (Quantum wells)

  • 73.63.Hs
73.23.-b (Electronic transport in mesoscopic systems) 73.20.At (Surface states, band structure, electron density of states)