Spin Relaxation and Decoherence through Chaotic Coupling
Abstract Book of the XXIII IUPAP International Conference on Statistical Physics, Genova, Italy, (9-13 July 2007)Abstract
The dynamics of a spin 1/2 coupled to few degrees of freedom which classical behavior is chaotic is presented. The chaotic system plays the role of an environment for the spin. Starting from a nonequilibrium initial condition for the whole system, spin relaxation and decoherence are studied both numerically and analytically. The numerical calculations are performed for a spin 1/2 in a uniform magnetic field coupled through Rashba interaction to a 2D chaotic billiard. Analytically, path integral calculations are performed considering the spin-orbit coupling in the weak regime. In this case, we show that the influence of the chaotic system on the spin dynamics is given by its correlation functions. Those functions are calculated semiclassically to take into account the chaotic behavior. Finally, we calculate the propagator of the spin reduced density matrix and we propagate spin states. We compare numerical and analitycal results.