Spectral asymmetries in the resonance fluorescence of two-level systems under pulsed excitation

TL;DR

This paper investigates the spectral features of two-level quantum systems under pulsed excitation, revealing multi-peak structures and asymmetries that differ from continuous driving, with implications for quantum dot systems and phonon interactions.

Contribution

It provides a detailed master equation analysis of resonance fluorescence under pulsed excitation, highlighting novel spectral asymmetries and multi-peak features not seen in steady-state conditions.

Findings

Identification of multi-peak spectral structures

Observation of off-resonant spectral asymmetry

Impact of electron-phonon coupling on fluorescence features

Abstract

We present an open-system master equation study of the coherent and incoherent resonance fluorescence spectrum from a two-level quantum system under coherent pulsed excitation. Several pronounced features which differ from the fluorescence under a constant drive are highlighted, including a multi-peak structure and a pronounced off-resonant spectral asymmetry, in stark contrast to the conventional symmetrical Mollow triplet. We also study semiconductor quantum dot systems using a polaron master equation, and show how the key features of dynamic resonance fluorescence change with electron--acoustic-phonon coupling.