Verifying bound entanglement of dephased Werner states

TL;DR

This paper demonstrates a method to fully verify entanglement, including bound entanglement, in noisy Werner states using entanglement quasiprobabilities, overcoming limitations of traditional criteria.

Contribution

The authors introduce a full entanglement verification method for dephased Werner states, revealing bound entanglement in noisy qutrit states with entanglement quasiprobabilities.

Findings

Bound entanglement can be verified in noisy qutrit Werner states.

Entanglement quasiprobabilities effectively detect full entanglement under noise.

The method surpasses traditional criteria like partial transposition.

Abstract

The verification of quantum entanglement under the influence of realistic noise and decoherence is crucial for the development of quantum technologies. Unfortunately, a full entanglement characterization is generally not possible with most entanglement criteria such as entanglement witnesses or the partial transposition criterion. In particular, so called bound entanglement cannot be certified via the partial transposition criterion. Here we present the full entanglement verification of dephased qubit and qutrit Werner states via entanglement quasiprobabilities. Remarkably, we are able to reveal bound entanglement for noisy-mixed states in the qutrit case. This example demonstrates the strength of the entanglement quasiprobabilities for verifying the full entanglement of quantum states suffering from noise.