论文标题
在Unruh-Dewitt检测器中量化质量能效应
Quantized mass-energy effects in an Unruh-DeWitt detector
论文作者
论文摘要
一个简单但功能强大的粒子检测器模型由一个两级系统组成，该系统耦合到一个场，其中检测到的粒子是场激发。这被称为Unruh-Dewitt检测器。使用该模型的研究通常集中在对检测器的外部自由度的完全经典描述上，或者是完整的现场理论处理，其中探测器本身被描述为一个领域。最近，人们对检测器质量中心的量子方面引起了极大的兴趣 - 要么被描述为沿着半经典轨迹移动，要么在非相关的哈密顿量下动态演变。但是，感兴趣的过程 - 场颗粒的吸收或排放 - 必定会通过吸收或发射的场量子的能量量来改变检测器的静止质量。以上模型都无法捕获这种效果。在这里，我们将检测器的质量能量的量化纳入Unruh-Dewitt模型中。我们显示，即使在最低能量限制中，由于发射或吸收引起的内部能量变化也是相关的。具体而言，除非忽略整个质量动态中心，否则由于检测器的质量变化而导致的过渡速率的校正不得忽略。我们的结果表明，如果不包括质量能量等效性，一个人不能将Unruh-Dewitt检测器作为巨大粒子的一致模型。
A simple but powerful particle detector model consists of a two-level system coupled to a field, where the detected particles are the field excitations. This is known as the Unruh-DeWitt detector. Research using this model has often focused on either a completely classical description of the external degrees of freedom of the detector, or a full field-theoretic treatment, where the detector itself is described as a field. Recently there has been much interest in quantum aspects of the detector's center of mass -- either described as moving in superposition along semiclassical trajectories, or dynamically evolving under a non-relativistic Hamiltonian. However, the processes of interest -- the absorption or emission of field particles -- necessarily change the detector's rest mass by the amount of energy of the absorbed or emitted field quanta. Neither of the above models can capture such effects. Here we incorporate the quantization of the detector's mass-energy into the Unruh-DeWitt model. We show that internal energy changes due to emission or absorption are relevant even in the lowest energy limit. Specifically, corrections to transition rates due to the detector's mass changing cannot be ignored unless the entire center of mass dynamics is also ignored. Our results imply that one cannot have a consistent model of the Unruh-DeWitt detector as a massive particle without including the mass-energy equivalence.
