Despite numerous proposals investigating various properties of accelerated detectors in different settings, detecting the Unruh effect remains challenging due to the typically weak signal at achievable accelerations. For an atom with frequency gap $ω_0$, accelerated in free space, significant acceleration-induced modification of properties like transition rates and radiative energy shifts requires accelerations of the order of $ω_0 c$. In this paper, we make the case for a suitably modified density of field states to be complemented by a judicious selection of the system property to be monitored. We study the radiative energy-level shift in inertial and uniformly accelerated atoms coupled to a massless quantum scalar field inside a cylindrical cavity. Uniformly accelerated atoms experience thermal correlations in the inertial vacuum, and the radiative shifts are expected to respond accordingly. We show that the noninertial contribution to the energy shift can be isolated and significantly enhanced relative to the inertial contribution by suitably modifying the density of field modes inside a cylindrical cavity. Moreover, we demonstrate that monitoring the radiative energy shift, as compared to transition rates, allows us to reap a stronger purely-noninertial signal. We find that a purely-noninertial radiative shift as large as 50 times the inertial energy shift can be obtained at small, experimentally achievable accelerations ($ a \sim 10^{-9} ω_{0} c$) if the cavity's radius $R$ is specified with a relative precision of $δR/R_{0} \sim 10^{-7}$. Given that radiative shifts for inertial atoms have already been measured with high accuracy, we argue that the radiative energy-level shift is a promising observable for detecting Unruh thermality with current technology.
Continuous variable methods in relativistic quantum information: Characterisation of quantum and classical correlations of scalar field modes in noninertial frames
Thermal and nonthermal scaling of the Casimir-Polder interaction in a black hole spacetime
本文研究了在黑洞背景中传播的无质量标量场介导的两个全同二能级原子间的Casimir-Polder力。我们研究了霍金辐射与Casimir-Polder力的相互作用，发现当原子处于事件视界附近时，Casimir-Polder相互作用能随原子间距离的变化呈现出从类热性质向非热性质的转变.我们证实了我们的研究结果的量子场准备在博尔韦尔，哈特尔霍金，和Unruh真空。我们的分析与相对论加速框架中二能级原子Casimir-Polder相互作用的非热特性一致[J. Marino et al.，物理修订信函113，020403（2014）]，其中已经观察到从与Unruh效应一致的热缩放到非热缩放的交叉。这两个交叉是一个结果的非惯性字符的背景下，调解卡西米尔相互作用传播的领域。在前一种情况下，特征交叉长度尺度与黑洞表面引力的倒数成正比，而在后一种情况下，特征交叉长度尺度由原子固有加速度的倒数决定。
