1207.6554 (F. Ciccarello et al.)

Collision-model-based approach to non-Markovian quantum dynamics    [PDF]

F. Ciccarello, G. M. Palma, V. Giovannetti

We present a theoretical framework to tackle quantum non-Markovian dynamics based on a microscopic collision model (CM), where the bath consists of a large collection of initially uncorrelated ancillas. Unlike standard memoryless CMs, we endow the bath with memory by introducing inter-ancillary collisions between next system-ancilla interactions. Our model interpolates between a fully Markovian dynamics and the continuous interaction of the system with a single ancilla, i.e., a strongly non-Markovian process. We show that in the continuos limit one can derive a general master equation, which while keeping such features is guaranteed to describe an unconditionally completely positive and trace-preserving dynamics. We also show that, for a specific choice of the involved couplings, known behaviors of an atomic system decaying in a damped cavity arise naturally in a suitable regime.

View original: http://arxiv.org/abs/1207.6554