Berlin 2008 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 31: Quantum dynamics, decoherence and quantum information

DY 31.1: Vortrag

Freitag, 29. Februar 2008, 10:15–10:30, MA 004

Nonexponential decoherence in a quantum Lévy kicked rotator — Henning Schomerus¹ and •Eric Lutz² — ¹Physics Department, Lancaster University, Lancaster, LA1 4YB, UK — ²Institute of Physics, University of Augsburg, D-86135 Augsburg

We investigate decoherence in the quantum kicked rotator (modeling cold atoms in a pulsed optical field) subjected to noise with power-law tail waiting-time distributions of variable exponent (Lévy noise). We demonstrate the existence of a regime of nonexponential decoherence where the notion of a decoherence rate is ill defined. In this regime, dynamical localization is never fully destroyed, indicating that the dynamics of the quantum system never reaches the classical limit. We show that this leads to quantum subdiffusion of the momentum, which should be observable in an experiment.