Optimal super dense coding over memory channels
  We study the super dense coding capacity in the presence of quantum channels with correlated noise. We investigate both the cases of unitary and non-unitary encoding. Pauli channels for arbitrary dimensions are treated explicitly. The super dense coding capacity for some special channels and resource states is derived for unitary encoding. We also provide an example of a memory channel where non-unitary encoding leads to an improvement in the super dense coding capacity. 
Zahra Shadman and Hermann Kampermann and Chiara Macchiavello and   Dagmar Bru{\ss}
quant-ph