Non-exponential decay in Floquet-Bloch bands

• Published in: arXiv.org
• Main Authors: Cao, Alec, Fujiwara, Cora J, Roshan Sajjad, Simmons, Ethan Q, Lindroth, Eva, Weld, David M
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 08.02.2020
• Subjects: Brittleness; Decay; Emitters; Fluorescence; Legal issues; Metastable state; Optical lattices; Parameter identification; Physics - Atomic Physics; Physics - Quantum Gases; Physics - Quantum Physics; Quantum mechanics; Time dependence; Variation
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2002.03051

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 non-exponential time dependence at both very short and very long times. Cold-atom experiments both classic and recent have proven to be powerful probes of fundamental decay processes; in this paper, we propose the use of Bose condensates in Floquet-Bloch bands as a probe of long-time non-exponential 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 quasienergy bands in a driven optical lattice.