Decoherence Cancellation through Noise Interference

We propose a novel, feedback-free method to cancel the effects of dephasing in the dynamics of open quantum systems. The protocol makes use of the coupling with an auxiliary system when they are both subjected to the same noisy dynamics in such a way that their interaction leads to cancellation of the noise on the system itself. This requires tuning the strength of the coupling between the main and auxiliary systems as well as the ability to prepare the auxiliary system in a Fock state, which solely depends on the coupling strength. We investigate the protocol’s efficiency to protect NOON states against dephasing in setups such as tweezer arrays of cold atoms. We show that the protocol’s efficiency is robust against fluctuations of the optimal parameters and, remarkably, that it is independent of the temporal features of the noise. Therefore, it could be applied to cancel both Markovian and non-Markovian dephasing noise, reaching regimes where error-correction protocols become inefficient.