Stabilizing entanglement in two-mode Gaussian states

TL;DR

This paper investigates how to maintain entanglement in two-mode Gaussian states under different dissipative processes, revealing limits and tradeoffs in stabilizing entanglement with various models.

Contribution

It provides new bounds on stabilizable entanglement in three dissipative models and refines the conditions for stabilizability in Gaussian systems.

Findings

Maximum entanglement is bounded in local damping and engineered dissipation models.

Arbitrary entanglement can be stabilized in cascaded oscillator models.

A tradeoff exists between entanglement and purity at maximum entanglement.

Abstract

We analyze the stabilizability of entangled two-mode Gaussian states in three benchmark dissipative models: local damping, dissipators engineered to preserve two-mode squeezed states, and cascaded oscillators. In the first two models, we determine principal upper bounds on the stabilizable entanglement, while in the last model, arbitrary amounts of entanglement can be stabilized. All three models exhibit a tradeoff between state entanglement and purity in the entanglement maximizing limit. Our results are derived from the Hamiltonian-independent stabilizability conditions for Gaussian systems. Here, we sharpen these conditions with respect to their applicability.