Interference-induced splitting of resonances in spontaneous emission

TL;DR

This paper investigates how quantum interference from spontaneous emission in a four-level atom causes resonance splitting and spectral modifications in fluorescence, revealing interference effects on atomic emission spectra.

Contribution

It demonstrates the impact of quantum interference on resonance splitting and spectral features in a four-level atomic system, providing a detailed physical explanation.

Findings

Resonance splitting occurs due to quantum interference from cascade decays.

Interference can enhance inner sidebands and narrow central peaks.

Dressed state analysis explains the numerical results.

Abstract

We study the resonance fluorescence from a coherently driven four-level atom in the Y-type configuration. The effects of quantum interference induced by spontaneous emission on the fluorescence properties of the atom are investigated. It is found that the quantum interference resulting from cascade emission decays of the atom leads to a splitting of resonances in the excited level populations calculated as a function of light detuning. For some parameters, interference assisted enhancement of inner sidebands and narrowing of central peaks may also occur in the fluorescence spectrum. We present a physical understandingof our numerical results using the dressed state description of the atom-light interaction.