Entanglement is protected by acceleration-induced transparency in thermal field

TL;DR

Problem: how acceleration-induced transparency (AIT) in a thermal field influences entanglement between two Unruh-DeWitt detectors. Approach: analytic treatment of two detectors with $H_{int}=\lambda\chi(τ)\mu(τ)\phi(t(τ),x(τ))$ interacting with a thermal scalar field, computation of transition amplitudes $I_{±}$ for nonuniform acceleration, construction of the $X$-state density $ρ_{out}$, and concurrence. Contributions: shows that AIT suppresses the stimulated absorption term while the Unruh term is amplified by $(\langle n\rangle+1)$, allowing residual entanglement to persist at specific energy gaps; higher background temperature reduces this residual entanglement and it vanishes beyond a critical temperature. Significance: provides a practical route to detecting Unruh-related detector responses in thermal environments and informs strategies to protect quantum correlations in noninertial quantum information tasks.

Abstract

The acceleration-induced transparency (AIT) effect has been suggested recently to amply the transition probability of the two-level detctor and offers a potential avenue for the experimental detection of the Unruh effect. In this paper, we explore the influence of the AIT effect on quantum entanglement between two detectors accelerated in a thermal field background, since the thermal backgound field cannot be avoided completely in any experiments. Interestingly, we find that although the backgound thermal field generally degrade the entanglement between the detectors, the AIT effect can effectively protect it.

Figures (3)

• Figure 1: Acceleration-induced transparency in thermal fields. The parameter is set to $\beta=0.1$, $v_{0}=1.041$, $v_{1}=1.070$, $T_{1}=9.74350$, $T_{2}=1305.413$.
• Figure 2: Entanglement behavior in thermal fields. The background field temperature $\beta= 0.3$ and the other parameters are the same as in Fig.1
• Figure 3: Residual entanglement as a function of background field temperature. The detector's energy gap is fixed at $\Omega=0.00762$, and the other parameters are the same as in Fig.1