Witnessing non-Markovianity of quantum evolution
  We provide further characterization of non-Markovian quantum dynamics based on the concept of divisible dynamical maps. In analogy to entanglement witness we propose a non-Markovianity witness and introduce the corresponding measure of non-Markovianity. We also provide characterization of non-Markovianity in terms of entropic quantities, fidelity and Wigner-Yanase-Dyson skew information. 
Dariusz Chru\'sci\'nski, Andrzej Kossakowski
quant-ph