Entanglement-annihilating and entanglement-breaking channels

TL;DR

This paper introduces a new class of quantum channels called entanglement-annihilating channels, which can destroy all entanglement in a system without necessarily being entanglement breaking, with analysis on local and multipartite cases.

Contribution

It defines and explores entanglement-annihilating channels, showing they differ from entanglement-breaking channels and analyzing their behavior in local and multipartite systems.

Findings

Entanglement-annihilating channels can destroy entanglement without breaking it.

Local noise effects vary with the number of subsystems in multipartite systems.

Single-qubit depolarizing channels exemplify the introduced concepts.

Abstract

We introduce and investigate a family of entanglement-annihilating channels. These channels are capable of destroying any quantum entanglement within the system they act on. We show that they are not necessarily entanglement breaking. In order to achieve this result we analyze the subset of locally entanglement-annihilating channels. In this case, the same local noise applied on each subsystem individually is less entanglement annihilating (with respect to multi-partite entanglement) as the number of subsystems is increasing. Therefore, the bipartite case provides restrictions on the set of local entanglement-annihilating channels for the multipartite case. The introduced concepts are illustrated on the family of single-qubit depolarizing channels.