Non-Markovianity degree for random unitary evolution
  We analyze the non-Markovianity degree for random unitary evolution of d-level quantum systems. It is shown how non-Markovianity degree is characterized in terms of local decoherence rates. In particular we derive a sufficient condition for vanishing of the back ow of information. 
Dariusz Chru\'sci\'nski and Filip A. Wudarski
quant-ph