中国物理B ›› 2016, Vol. 25 ›› Issue (6): 67301-067301.doi: 10.1088/1674-1056/25/6/067301

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

Topological charge pump by surface acoustic waves

Yi Zheng(郑一), Shi-Ping Feng(冯世平), Shi-Jie Yang(杨师杰)   

  1. Department of Physics, Beijing Normal University, Beijing 100875, China
  • 收稿日期:2015-09-22 修回日期:2016-03-03 出版日期:2016-06-05 发布日期:2016-06-05
  • 通讯作者: Shi-Jie Yang E-mail:yangshijie@tsinghua.org.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant No. 11374036) and the National Basic Research Program of China (Grant No. 2012CB821403).

Topological charge pump by surface acoustic waves

Yi Zheng(郑一), Shi-Ping Feng(冯世平), Shi-Jie Yang(杨师杰)   

  1. Department of Physics, Beijing Normal University, Beijing 100875, China
  • Received:2015-09-22 Revised:2016-03-03 Online:2016-06-05 Published:2016-06-05
  • Contact: Shi-Jie Yang E-mail:yangshijie@tsinghua.org.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant No. 11374036) and the National Basic Research Program of China (Grant No. 2012CB821403).

摘要:

Quantized electron pumping by the surface acoustic wave across barriers created by a sequence of split metal gates is interpreted from the viewpoint of topology. The surface acoustic wave serves as a one-dimensional periodical potential whose energy spectrum possesses the Bloch band structure. The time-dependent phase plays the role of an adiabatic parameter of the Hamiltonian which induces a geometrical phase. The pumping currents are related to the Chern numbers of the filled bands below the Fermi energy. Based on this understanding, we predict a novel effect of quantized but non-monotonous current plateaus simultaneously pumped by two homodromous surface acoustic waves.

关键词: quantized pumping, surface acoustic wave, topological band structure

Abstract:

Quantized electron pumping by the surface acoustic wave across barriers created by a sequence of split metal gates is interpreted from the viewpoint of topology. The surface acoustic wave serves as a one-dimensional periodical potential whose energy spectrum possesses the Bloch band structure. The time-dependent phase plays the role of an adiabatic parameter of the Hamiltonian which induces a geometrical phase. The pumping currents are related to the Chern numbers of the filled bands below the Fermi energy. Based on this understanding, we predict a novel effect of quantized but non-monotonous current plateaus simultaneously pumped by two homodromous surface acoustic waves.

Key words: quantized pumping, surface acoustic wave, topological band structure

中图分类号:  (Surface states, band structure, electron density of states)

  • 73.20.At
73.21.Hb (Quantum wires) 72.50.+b (Acoustoelectric effects)