Entanglement detection beyond the cross-norm or realignment criterion

TL;DR

This paper introduces a new, computationally simple criterion for detecting quantum entanglement that surpasses existing methods like the dV criterion, effectively identifying entanglement in bound states and generalizing to multipartite systems.

Contribution

The authors develop a novel separability criterion that is stronger than current criteria and can be extended to multipartite quantum systems.

Findings

Detects entanglement in many bound entangled states

Stronger than the dV criterion and realignment criterion

Generalizable to even-partite systems

Abstract

Separability problem, to decide whether a given state is entangled or not, is a fundamental problem in quantum information theory. We propose a powerful and computationally simple separability criterion, which allows us to detect the entanglement of many bound entangled states. The criterion is strictly stronger than the dV criterion, the computable cross-norm or realignment criterion and its optimal nonlinear entanglement witnesses. Furthermore, this criterion can be generalized to an analogue of permutation separability criteria in the even-partite systems.