Probing the Non-exponential Decay Regime in Open Quantum Systems

TL;DR

This paper explores the long-term non-exponential decay behavior in open quantum systems, proposing new observables for experimental detection, with implications across various physical systems beyond atomic nuclei.

Contribution

It introduces novel observables for detecting non-exponential decay regimes in open quantum systems, extending the understanding beyond early-time decay observations.

Findings

Proposes observables for long-term decay analysis

Highlights non-exponential decay in various quantum systems

Connects decay behavior to initial wave function components

Abstract

The most important law of radioactivity is that of the exponential decay. In the realm of quantum mechanics, however, this decay law is neither rigorous nor fundamental. The deviations from the exponential decay have been observed experimentally at the early stage of a decay process, but there is little evidence for non-exponential behavior at long times. Yet such long-term non-exponentiality is expected theoretically to probe the non-resonant background components of the initial wave function which preserve the structural interference and the memory of how the state was created. In this paper, we propose new observables that can be used for experimental investigations of the post-exponential decay regime, including the decay of threshold resonances, particle correlations in three-body decays, and interference between near-lying resonances. While the specific examples presented in this work pertain to atomic nuclei, the properties of non-exponential decay are generic, i.e., they apply to other many-body open quantum systems, such as hadrons, atoms, molecules, and nanostructures.