arXiv subjects

A. V. Bulinski

Publications and source records attributed to A. V. Bulinski.

2 recordsLinked to original sources

arXiv2020

On quantum channels and operations preserving finiteness of the von Neumann entropy

We describe the class (semigroup) of quantum channels mapping states with finite entropy into states with finite entropy. We show, in particular, that this class is naturally decomposed into three convex subclasses, two of them are closed under concatenations and tensor products. We obtain asymptotically tight universal continuity bounds for the output entropy of two types of quantum channels: channels with finite output entropy and energy-constrained channels preserving finiteness of the entropy.

quant-ph↗

arXiv2017

Lower bounds on distances between a given quantum channel and certain classes of channels

The tight, in a sense, lower estimates of diamond-norm distance from a given quantum channel to the sets of degradable, antidegradable and entanglement-breaking channels are obtained via the tight continuity bounds for quantum mutual information and for relative entropy of entanglement in finite-dimensional case. As an auxiliary result there are established lower bounds of trace-norm distance from a given bipartite state to the set of all separable states.

quant-ph↗