Using squeezed field to preserve two-atom entanglement against spontaneous emissions

TL;DR

This paper proposes a method using a squeezed field to control and partially preserve entanglement between two atoms in a cavity, counteracting spontaneous emission decoherence effects.

Contribution

It introduces a controllable interaction via a squeezed field to protect atom entanglement from amplitude damping decoherence.

Findings

Partial entanglement preservation in independent damping channels

Enhanced entanglement in collective damping scenarios

Strategy effectiveness depends on initial entanglement levels

Abstract

Tunable interaction between two atoms in a cavity is realized by interacting the two atoms with an extra controllable single-mode squeezed field. Such a controllable interaction can be further used to control entanglement between the two atoms against amplitude damping decoherence caused by spontaneous emissions. For the independent amplitude damping decoherence channel, entanglement will be lost completely without controls, while it can be partially preserved by the proposed strategy. For the collective amplitude damping decoherence channel, our strategy can enhance the entanglement compared with the uncontrolled case when the entanglement of the uncontrolled stationary state is not too large.