Entanglement dynamics and Bell Violations of two atoms in Tavis-Cummings model with phase decoherence

TL;DR

This paper investigates how phase decoherence affects entanglement and Bell violations in a two-atom Tavis-Cummings model, revealing conditions under which entanglement persists or diminishes and how Bell violations relate to entanglement.

Contribution

It provides a detailed analysis of entanglement dynamics and Bell violations in the presence of phase decoherence, highlighting conditions for sustained maximal entanglement.

Findings

Entanglement exhibits periodic behavior without decoherence.

Phase decoherence causes entanglement decay, but can stabilize it at a constant value.

Bell violation and entanglement are not always monotonically related.

Abstract

Considering the dipole-dipole coupling intensity between two atoms and the field in the Fock state, the entanglement dynamics between two atoms that are initially entangled in the system of two two-level atoms coupled to a single mode cavity in the presence of phase decoherence has been investigated. The two-atom entanglement appears with periodicity without considering phase decoherence, however, the phase decoherence causes the decay of entanglement between two atoms, with the increasing of the phase decoherence coefficient, the entanglement will quickly become a constant value, which is affected by the two-atom initial state, Meanwhile the two-atom quantum state will forever stay in the maximal entangled state when the initial state is proper even in the presence of phase decoherence. On the other hand, the Bell violation and the entanglement does not satisfy the monotonous relation, a large Bell violation implies the presence of a large amount of entanglement under certain conditions, while a large Bell violation corresponding to a little amount of entanglement in certain situations. However, the violation of Bell-CHSH inequality can reach the maximal value if two atoms are in the maximal entangled state, or vice versa.