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DY: Fachverband Dynamik und Statistische Physik
DY 57: Poster - Diffusion
DY 57.8: Poster
Thursday, March 19, 2015, 16:00–18:00, Poster A
Non-adiabatic quantum pumping by a randomly moving potential barrier — Stanislav Dervyanko1 and •Daniel Waltner2 — 1Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel — 2Fakultät für Physik, Universität Duisburg-Essen, Lotharstr. 1, 47048 Duisburg
We look at random AC fluctuations of the electrical charge in an open 1D quantum system where the potential barrier experiences random lateral motion in time. Our treatment is essentially non-adiabatic. Both diffusive and ballistic (Lévy) regimes are considered. For a finite size system the probability current as well as the net accumulated electric charge experience random fluctuations over the static background. We show that in the large-time limit t → ∞ the wavefunction is naturally separated into the Berry-phase component (resulting from the singular part of the wave amplitude in the co-moving frame) and the non-adiabatic correction (arising from fast oscillating, slow decaying tails of the same amplitude). In the special limit of delta-correlated continuous Gaussian random walk we obtain a closed analytical expressions for the ensemble averaged amplitude in the co-moving frame and demonstrate that the main contribution to the average wavefunction and probability current comes from the Berry-phase component.