Eur. Phys. J. B 78, 475-479 (2010)
https://doi.org/10.1140/epjb/e2010-10644-4

Quantum pump in an Aharonov-Bohm interferometer with a quantum dot driven by an ac field

¹ Department of Physics, Beijing University of Aeronautics and Astronautics, Beijing, 100191, P.R. China
² Department of Physics, Tsinghua University, Beijing, 100084, P.R. China

Corresponding author: ^a hpan@buaa.edu.cn

Received: 24 August 2010
Revised: 13 October 2010
Published online: 10 December 2010

Abstract

With the help of the nonequilibrium Green's function method, the quantum pump in an Aharonov-Bohm interferometer with a quantum dot driven by an ac field are studied theoretically. The ac field applied to the quantum dot may give rise to a pumped charge current at zero-bias voltage in the presence of a nonzero magnetic flux. The possibility of manipulating the pumped charge current is explored by tuning the dot level, the magnetic flux, the coupling strength and the ac field. By making use of various tunings, the magnitude and direction of the pumped charge current can be well controlled. Furthermore, the possibility to generate a pure spin current in the presence of the Rashba spin-orbit interaction has been discussed, which provides an idea for the design of a spin pump electrically.