During an adiabatic pumping cycle a conventional two-barrier quantum device takes an electron from the left lead and ejects it to the right lead. Hence, the pumped charge per cycle is naively expected to be Q ≤ e. This zero-order adiabatic point of view is in fact misleading. For a closed device we can get Q > e and even Q ≫ e. In this paper, a detailed analysis of the quantum pump operation is presented. Using the Kubo formula for the geometric conductance, and applying the Dirac chains picture, we derive practical estimates for Q.
ASJC Scopus subject areas
- Statistical and Nonlinear Physics
- Mathematical Physics
- Physics and Astronomy (all)