Entanglement of quantum oscillators coupled to different heat baths

TL;DR

This paper investigates how two coupled quantum oscillators interacting with different heat baths exhibit entanglement properties, identifying critical temperatures for entanglement disappearance and exploring conditions for hot entanglement.

Contribution

It introduces a detailed analysis of entanglement dynamics in coupled oscillators with different heat bath temperatures and damping parameters, highlighting conditions for high-temperature entanglement.

Findings

Critical temperatures for entanglement depend on damping parameters and bath temperatures.

Large differences in damping parameters can lead to very high critical temperatures.

Possibility of hot entanglement when one oscillator's critical temperature is much larger than its frequency.

Abstract

We study the non-equilibrium dynamics of two coupled oscillators interacting with their own heat baths of quantum scalar fields at different temperature $T_1$ and $T_2$ with bilinear couplings between them. We particularly focus on the entanglement or inseparability property of their quantum states. The critical temperatures of two respective oscillators, $T_{1c}$ and $T_{2c}$, higher than which the entanglement disappears, can be determined. It is found that when two damping parameters are largely different, say $\gamma_1 \ll \gamma_2$, the critical temperature $T_{1c}$ with respect to the frequency $\Omega_+$, the higher frequency among two normal modes frequencies, can be very large, $T_{1c} \gg \Omega_+$, while $T_{2c} \propto \Omega_+$ with the possibility of hot entanglement. The entanglement of two oscillators with the temperature-dependent damping parameters $\gamma_{1;2,T}$ from heat baths is also discussed.