Hidden entanglement in the presence of random telegraph dephasing noise

TL;DR

This paper explains how entanglement revivals in two qubits affected by random telegraph noise can be understood through the concept of hidden entanglement, which can be recovered with local operations.

Contribution

It introduces the concept of hidden entanglement to explain entanglement revivals under pure dephasing noise without nonlocal operations.

Findings

Entanglement exhibits revivals despite local noise effects.

Hidden entanglement can be recovered with local operations.

Revival phenomena are explained by the hidden entanglement concept.

Abstract

Entanglement dynamics of two noninteracting qubits, locally affected by random telegraph noise at pure dephasing, exhibits revivals. These revivals are not due to the action of any nonlocal operation, thus their occurrence may appear paradoxical since entanglement is by definition a nonlocal resource. We show that a simple explanation of this phenomenon may be provided by using the (recently introduced) concept of "hidden" entanglement, which signals the presence of entanglement that may be recovered with the only help of local operations.