A qualitative perspective on the dynamics of a single-Cooper-pair box with a phase-damped cavity

TL;DR

This paper investigates how a phase-damped cavity can sustain long-lived entanglement in a single-Cooper-pair box system, revealing environment-dependent coherence loss and entanglement dynamics.

Contribution

It provides a qualitative analysis of transient entanglement in a Cooper-pair box influenced by phase damping, highlighting the environment's role in entanglement persistence.

Findings

Phase-damped cavity can induce long-lived entanglement.

Asymptotic coherence loss is independent of interaction development.

Entanglement survival depends critically on environmental effects.

Abstract

In a recent paper Dajka, et.al., [J. Phys. A \textbf{40}, F879 (2007)] predicted that some composite systems can be entangled forever even if coupled with a thermal bath. We analyze the transient entanglement of a single-Cooper-pair box biased by a classical voltage and irradiated by a quantized field and find the unusual feature that the phase-damped cavity can lead to a long-lived entanglement. The results show an asymptotic value of the idempotency defect (concurrence) which embodies coherence loss (entanglement survival), independent of the interaction development by dependent critically on environment.