We provide a simple class of 2-qudit states for which one is able to formulate necessary and sufficient conditions for separability. As a byproduct we generalize well known construction provided by Horodecki et al. for d=3. It is hoped that these sta
tes with known separability/entanglement properties may be used to test various notions in entanglement theory.
Complete characterization of complete positivity preserving non-Markovian master equations is presented.
A sufficient condition for non-Markovian master equation which ensures the complete positivity of the resulting time evolution is presented.
Non-Markovian reduced dynamics of an open system is investigated. In the case the initial state of the reservoir is the vacuum state, an approximation is introduced which makes possible to construct a reduced dynamics which is completely positive.
