Dinâmica não-markoviana em ambientes estruturados com desordem correlacionada

Abstract

Manipulating the dynamics of open quantum systems is a crucial requerirement for large scale quantum computers. Finding ways to overcome or extend decoherence times is a very challenging goal. Already at the level of a single qubit, its reduced dynamics in respect to a larger reservoir can be very complex. Structured reservoirs, for instance, can lead to various regimes other than the standard Markovian spotaneous emission. Here we go along these lines and consider a single atom coupled to an array of coupled cavities in the presence of on-site correlated disorder. The correlation is long ranged and is associated to the trace of a fractional Brownian motion following a power-law spectrum. The cavity modes play the role of a structured dissipative environment. We then study the dynamics of an atomic excitation released from one of the cavities to spread over the coupled cavity array under different disorder configurations. We explore the non-Markovian emission regimes, involving the return of information to the main system depending on the correlation degree embedded in the disorder. We find that we can control the degree of non-Markovianity in the emission dynamics by tuning the disorder correlation exponent. Our results offer prospects for the engineering of controled reservoirs in quantum devices.