Time-invariant entanglement and sudden death of non-locality

TL;DR

This paper explores how entanglement can remain constant while non-locality may suddenly disappear or become trapped in two qubits affected by dephasing, combining theoretical analysis and experiments.

Contribution

It reveals the coexistence of frozen entanglement and dynamic non-locality behavior in a dephasing environment, highlighting novel quantum phenomena.

Findings

Entanglement can be permanently frozen despite system evolution.

Non-locality can abruptly vanish or become trapped during dynamics.

Experimental validation confirms theoretical predictions.

Abstract

We investigate both theoretically and experimentally the dynamics of entanglement and non-locality for two qubits immersed in a global pure dephasing environment. We demonstrate the existence of a class of states for which entanglement is forever frozen during the dynamics, even if the state of the system does evolve. At the same time non-local correlations, quantified by the violation of the Clauser-Horne-Shimony-Holt (CHSH) inequality, either undergo sudden death or are trapped during the dynamics.