Lower Bound of Concurrence Based on Positive Maps

TL;DR

This paper derives an explicit analytical lower bound for the concurrence of bipartite quantum systems, enhancing entanglement detection beyond existing criteria like PPT and realignment.

Contribution

It introduces a new lower bound for concurrence that outperforms several well-known entanglement detection methods.

Findings

Detects entanglement more effectively in certain states

Improves upon PPT and realignment bounds

Provides a practical analytical tool for quantum entanglement analysis

Abstract

We study the concurrence of arbitrary dimensional bipartite quantum systems. An explicit analytical lower bound of concurrence is obtained, which detects entanglement for some quantum states better than some well-known separability criteria, and improves the lower bounds such as from the PPT, realignment criteria and the Breuer's entanglement witness.