Berlin 2008 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 27: Quantum chaos II
DY 27.10: Vortrag
Donnerstag, 28. Februar 2008, 16:45–17:00, MA 004
Dephasing in quantum chaotic transport (semiclassical approach) — Robert S. Whitney1, Philippe Jacquod2, and •Cyril Petitjean3,4 — 1Institut Laue-Langevin, Grenoble, France — 2Physics Department, University of Arizona, Tucson, USA — 3Département de Physique Théorique, Genève, Switzerland — 4Institut für Theoretische Physik, Universität Regensburg, Regensburg, Germany
Electronic systems in the mesoscopic regime are ideal testing-grounds for investigating the quantum-to-classical transition. Quantum coherence conservation in these systems is usually determined by the ratio of the dephasing time τφ to some relevant classical time scale.
We investigate the effect of dephasing on quantum transport through a two-terminal chaotic dot in the deep semiclassical limit. The decoherence originating from: an external quantum chaotic environment, a classical noise, a voltage probe. We find an exponential suppression of weak-localization ∝ exp[−τ/τφ] in addition to the universal algebraic suppression of weak localization. The parameter τ depends strongly on the source of dephasing. For a voltage probe, is of order the Ehrenfest time. In contrast, for a chaotic environment or a classical noise, where is related to the correlation length of the coupling/noise potential. We show also that the Fano factor is unaffected by decoherence. We connect these results to earlier works on dephasing due to electron-electron interactions, and numerically confirm our findings.
[1] Petitjean, Jacquod, Whitney, JETP Letters 86, 736 (2007),
[2] Whitney, Jacquod ,Petitjean, arXiv:0710.5137v1