Berlin 2008 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 17: Poster I

DY 17.8: Poster

Tuesday, February 26, 2008, 16:00–18:00, Poster C

Spin Relaxation and Decoherence through Chaotic Coupling — •Marcus V. S. Bonança and Klaus Richter — Institut für Theoretische Physik, Universität Regensburg, D-93040, Germany

We present numerical results and also the strategy for analytical calculations of the dynamics of a spin 1/2 (or a two-level system) coupled to two degrees of freedom which classical dynamics is chaotic. The chaotic system plays the role of an environment for the spin. It has been shown in the literature that such low-dimensional chaotic systems can induce relaxation and decoherence processes in simple systems coupled to them. The motivation behind such works is to understand better the role played by the dynamics in those irreversible phenomena. Our goal is to investigate a relation between the origin of the spin relaxation and decoherence and the chaoticity even when quantum effects are taken into account in the environment dynamics. Starting from a product initial state for the whole system, we study the spin effective dynamics numerically and analytically. Path integral calculations in close analogy to the spin-boson model are performed. Semiclassical methods are used to incorporate quantum effects in the correlation functions of the chaotic system.