Abstract Exponential decay laws describe systems ranging from unstable nuclei to fluorescent molecules, in which the probability of jumping to a lower-energy state in any given time interval is static and history-independent. These decays, involving only a metastable state and fluctuations of the quantum vacuum, are the most fundamental nonequilibrium process and provide a microscopic model for the origins of irreversibility. Despite the fact that the apparently universal exponential decay law has been precisely tested in a variety of physical systems, it is a surprising truth that quantum mechanics requires that spontaneous decay processes have nonexponential time dependence at both very short and very long times. Cold-atom experiments have proven to be powerful probes of fundamental decay processes; in this article, we propose the use of Bose condensates in Floquet–Bloch bands as a probe of long-time nonexponential decay in single isolated emitters. We identify a range of parameters that should enable observation of long-time deviations and experimentally demonstrate a key element of the scheme: tunable decay between quasi-energy bands in a driven optical lattice.

中文翻译：

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探索 Floquet-Bloch 带中的非指数衰减

摘要 指数衰减定律描述了从不稳定原子核到荧光分子的系统，其中在任何给定时间间隔内跃迁到较低能量状态的概率是静态的且与历史无关。这些衰变仅涉及量子真空的亚稳态和波动，是最基本的非平衡过程，并为不可逆性的起源提供了微观模型。尽管表面上普遍的指数衰减定律已经在各种物理系统中进行了精确测试，但令人惊讶的是，量子力学要求自发衰减过程在非常短和非常长的时间内都具有非指数时间依赖性。冷原子实验已被证明是对基本衰变过程的有力探索。在本文中，我们建议在 Floquet-Bloch 波段中使用 Bose 凝聚物作为单个孤立发射体中长期非指数衰减的探针。我们确定了一系列参数，这些参数应该能够观察长期偏差，并通过实验证明该方案的一个关键要素：驱动光学晶格中准能带之间的可调衰减。