中国物理B ›› 2015, Vol. 24 ›› Issue (11): 117202-117202.doi: 10.1088/1674-1056/24/11/117202

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

Adiabatic quantum pump in a zigzag graphene nanoribbon junction

张林   

  1. Department of Applied Physics, College of Science, Nanjing Forestry University, Nanjing 210037, China
  • 收稿日期:2015-04-20 修回日期:2015-07-19 出版日期:2015-11-05 发布日期:2015-11-05
  • 通讯作者: Zhang Lin E-mail:lzhang2010@163.com
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 110704033), the Natural Science Foundation of Jiangsu Province, China (Grant No. BK2010416), and the Natural Science Foundation for Colleges and Universities in Jiangsu Province, China (Grant No. 13KJB140005).

Adiabatic quantum pump in a zigzag graphene nanoribbon junction

Zhang Lin (张林)   

  1. Department of Applied Physics, College of Science, Nanjing Forestry University, Nanjing 210037, China
  • Received:2015-04-20 Revised:2015-07-19 Online:2015-11-05 Published:2015-11-05
  • Contact: Zhang Lin E-mail:lzhang2010@163.com
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 110704033), the Natural Science Foundation of Jiangsu Province, China (Grant No. BK2010416), and the Natural Science Foundation for Colleges and Universities in Jiangsu Province, China (Grant No. 13KJB140005).

摘要: The adiabatic electron transport is theoretically studied in a zigzag graphene nanoribbon (ZGNR) junction with two time-dependent pumping electric fields. By modeling a ZGNR p-n junction and applying the Keldysh Green’s function method, we find that a pumped charge current is flowing in the device at a zero external bias, which mainly comes from the photon-assisted tunneling process and the valley selection rule in an even-chain ZGNR junction. The pumped charge current and its ON and OFF states can be efficiently modulated by changing the system parameters such as the pumping frequency, the pumping phase difference, and the Fermi level. A ferromagnetic ZGNR device is also studied to generate a pure spin current and a fully polarized spin current due to the combined spin pump effect and the valley valve effect. Our finding might pave the way to manipulate the degree of freedom of electrons in a graphene-based electronic device.

关键词: quantum pump, zigzag graphene nanoribbon, pseudo-parity, current

Abstract: The adiabatic electron transport is theoretically studied in a zigzag graphene nanoribbon (ZGNR) junction with two time-dependent pumping electric fields. By modeling a ZGNR p-n junction and applying the Keldysh Green’s function method, we find that a pumped charge current is flowing in the device at a zero external bias, which mainly comes from the photon-assisted tunneling process and the valley selection rule in an even-chain ZGNR junction. The pumped charge current and its ON and OFF states can be efficiently modulated by changing the system parameters such as the pumping frequency, the pumping phase difference, and the Fermi level. A ferromagnetic ZGNR device is also studied to generate a pure spin current and a fully polarized spin current due to the combined spin pump effect and the valley valve effect. Our finding might pave the way to manipulate the degree of freedom of electrons in a graphene-based electronic device.

Key words: quantum pump, zigzag graphene nanoribbon, pseudo-parity, current

中图分类号:  (Spin polarized transport in semiconductors)

  • 72.25.Dc
72.80.Vp (Electronic transport in graphene) 72.25.Mk (Spin transport through interfaces)