Nonlinear coupler operating on Werner-like states - entanglement creation, its enhancement and preservation

TL;DR

This paper explores a model of two coupled nonlinear oscillators starting from Werner-like states, demonstrating entanglement creation, enhancement, preservation, and phenomena like sudden death and rebirth under damping.

Contribution

It introduces a model where entanglement dynamics from Werner-like states are analyzed in a nonlinear Kerr system with damping effects, revealing entanglement preservation and complex phenomena.

Findings

Pure two-qubit entangled states can be generated.

Entanglement can survive damping effects.

Sudden death and rebirth of entanglement can occur.

Abstract

We discuss a model of two nonlinear Kerr-like oscillators, mutually coupled and excited by parametric process. We show that the system's evolution, starting from Werner-like states, remains closed within a small set of two-mode n-photon states the system, and pure two-qubit entangled state can be generated. For some initial Werner-like states delayed entanglement generation can be observed. We investigate the influence of two damping mechanisms on the system's evolution. We show that for the both cases, the entanglement can survive despite the presence of damping, and the effects of sudden entanglement death and its rebirth can appear in the system.