Turnstile pumping through an open quantum wire

Abstract

We use a non-Markovian generalized master equation (GME) to describe the time-dependent charge transfer through a parabolically confined quantum wire of a finite length coupled to semi-infinite quasi two-dimensional leads. The quantum wire and the leads are in a perpendicular external magnetic field. The contacts to the left and right leads depend on time and are kept out of phase to model a quantum turnstile of finite size. The effects of the driving period of the turnstile, the external magnetic field, the character of the contacts, and the chemical potential bias on the effectiveness of the charge transfer of the turnstile are examined, both in the absence and in the presence of the magnetic field. The interplay between the strength of the coupling and the strength of the magnetic field is also discussed. We observe how the edge states created in the presence of the magnetic field contribute to the pumped charge.Comment: RevTeX (pdf-LaTeX), 9 pages with 12 included jpg figure