Memory effects in a Markov chain dephasing channel
  We study a dephasing channel with memory, modelled by a Markov chain. We show that even weak memory effects have a detrimental impact on the performance of quantum error correcting schemes designed for uncorrelated errors. We also discuss an alternative scheme that takes advantage of memory effects to protect quantum information. 
Antonio D'Arrigo, Elena De Leo, Giuliano Benenti, Giuseppe Falci