# The exponential-nonexponential transition in quantum decay as a phenomenon of interference in time domain of the decaying particle with itself

## TL;DR

This paper uses an exact non-Hermitian approach to analyze quantum decay, revealing that the transition from exponential to nonexponential decay results from interference in the time domain of the decaying particle with itself.

## Contribution

It introduces a precise analytical method employing resonance states to describe the exponential to nonexponential decay transition in quantum systems.

## Key findings

- Decay transition is due to interference in time domain.
- Exact analytical expression for decay wave function.
- Identification of physical mechanism behind decay transition.

## Abstract

By using an exact analytical non-Hermitian approach in terms of resonance (quasinormal) states we express the decaying wave function as the sum of exponential and nonexponential decaying solutions to the time-dependent Schr\"odinger equation. We show that the exponential-nonexponential transition of decay at long times represents physically a process of interference in time domain of the decaying particle with itself.