The Adiabatic Wigner-Weisskopf Model

TL;DR

This paper extends the Wigner-Weisskopf model to include slowly varying time-dependent atomic interactions, analyzing atomic decay and photon buildup under adiabatic and small coupling conditions.

Contribution

It introduces a time-dependent generalization of the Wigner-Weisskopf model and analyzes its dynamics in various regimes, including decay and photon excitation buildup.

Findings

Describes atomic radiative decay in the time-dependent model

Analyzes photon field excitation buildup

Provides insights into adiabatic and small coupling regimes

Abstract

We consider a slowly varying time dependent d-level atom interacting with a photon field. Restricted to the single excitation atom-field sector, the model is a time-dependent generalization of the Wigner-Weisskopf model describing spontaneous emission of an atomic excitation into the radiation field. We analyze the dynamics of the atom and of the radiation field in the adiabatic and small coupling approximations, in various regimes. In particular, starting with an excited atomic state, we provide a description of both the radiative decay of the atom and of the buildup of the photon excitation in the field.