Defining the moving preferred basis

MARIO CASTAGNINO; SEBASTIAN FORTIN

Trieste

Workshop; Workshop on New Trends in Quantum Dynamics and Entanglement; 2011

ICTP

There are many formalisms to describe quantum decoherence. However, many of them give non general and ad hoc definition of "pointer basis" or "moving preferred basis", and this fact is a problem for the decoherence program. In our contribution, using the well known Environment Induced Decoherence formalism, we will consider quantum systems under a general theoretical framework for decoherence and present a tentative very general definition of the moving preferred basis and the relaxation and decoherence times. The formalism is based on finding the poles of the Hamiltonian and from them all the possible decaying modes of the non-unitary evolution of the open quantum system. Since the catalogue of the poles contains the whole information about the decoherence process, one should be able to define the decoherence time and the preferred basis from this catalogue. This preferred basis is implemented, and the characteristic times are computed, in a well known open system model with a Hamiltonian of an oscillator in a bath of oscillators and a rotating wave interaction. The obtained decoherence and the relaxation times coincide with those of a similar model of Omnès.