Backreaction and the Unruh effect: New insights from exact solutions of uniformly accelerated detectors
Backreaction and the Unruh effect: New insights from exact solutions of uniformly accelerated detectors
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逆反应和安鲁效应：均匀加速探测器精确解的新见解
DOI：
10.1103/physrevd.76.064008
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发表时间：
2006
影响因子：
5
通讯作者：
B. Hu
中科院分区：
文献类型：
--
作者：
Shih;B. Hu
利用最近获得的均匀加速Unruh-DeWitt探测器的非微扰结果，我们发现了探测器内部自由度动态演化的新特征，并确定了最初源自时间相关微扰理论的Unruh效应在超弱耦合和超高加速度极限下起作用。探测器和场之间的相互作用会在它们之间产生纠缠，并且即使对于在明可夫斯基真空中静止的探测器来说，追踪场也会导致探测器的混合状态。我们基于这个精确解决方案的发现清楚地表明了与忽略量子场反反应的普通结果的差异，因为探测器不再像完美的温度计一样工作。通过对探测器约简密度矩阵演化的计算，我们发现，在与时间相关的微扰理论推导的无限长的相互作用持续时间内，从初始基态的跃迁概率仅存在于对应于马尔可夫体系的特殊限制条件下的瞬态精确解中。此外，探测器在后期从未在自由探测器的能量本征态上看到精确的玻尔兹曼分布，因此在覆盖更广泛范围的参数的非马尔可夫体系中，无法在探测器内部识别昂鲁温度。
Using nonperturbative results obtained recently for a uniformly accelerated Unruh-DeWitt detector, we discover new features in the dynamical evolution of the detector's internal degree of freedom, and identified the Unruh effect derived originally from time-dependent perturbation theory as operative in the ultraweak coupling and ultrahigh acceleration limits. The mutual interaction between the detector and the field engenders entanglement between them, and tracing out the field leads to a mixed state of the detector even for a detector at rest in Minkowski vacuum. Our findings based on this exact solution show clearly the differences from the ordinary result where the quantum field's backreaction is ignored in that the detector no longer behaves like a perfect thermometer. From a calculation of the evolution of the reduced density matrix of the detector, we find that the transition probability from the initial ground state over an infinitely long duration of interaction derived from time-dependent perturbation theory is existent in the exact solution only in transient under special limiting conditions corresponding to the Markovian regime. Furthermore, the detector at late times never sees an exact Boltzmann distribution over the energy eigenstates of the free detector, thus in the non-Markovian regime covering a wider range ofmore » parameters the Unruh temperature cannot be identified inside the detector.« less