Evolution of entanglement for quantum mixed states

TL;DR

This paper introduces a simple relation for concurrence that provides a lower bound on the entanglement of bipartite mixed states after physical processes, applicable to high-dimensional systems.

Contribution

It presents a new lower bound for concurrence of mixed bipartite states, extending previous upper bounds and applicable to high-dimensional systems.

Findings

Provides a lower bound for concurrence after physical processes.

Applicable to high-dimensional bipartite quantum systems.

Includes pure states as a special case.

Abstract

A simple relation is introduced for concurrence to describe how much the entanglement of bipartite system is at least left if either (or both) subsystem undergoes an arbitrary physical process. This provides a lower bound for concurrence of mixed states (pure states are included) in contrast to the upper bound given by Konrad et al [Nature Physics \textbf{4}, 99 (2008)]. Our results are also suitable for a general high dimensional bipartite quantum systems.