Noise suppression via generalized-Markovian processes

It is by now well established that noise itself can be useful for performing quantum information processing tasks.
We present results which show how one can effectively reduce the error rate associated with a noisy quantum channel, by counteracting its detrimental effects with another form of noise.
In particular, we consider the interplay between a purely Markovian (Lindblad) dynamics, and a more general form of dissipation, which we refer to as generalized-Markovian noise. This noise has an associated memory kernel and the resulting dynamics is described by an integro-differential equation (i.e., it has a non-Markov character).
The overall dynamics are characterized by decay rates which depend not only on the original dissipative time-scales, but also on the new integral kernel. We find that one can engineer this kernel such that the overall rate of decay is lowered by the addition of such a noise term.
We provide numerical results for several physical models, including a dephasing channel, and qubit in a thermal environment.
These results help to qualitatively explain the physical mechanism behind this error suppression scheme, whereby the system is periodically decoupled from the background noise.