Near-field spectra of quantum well excitons with non-Markovian phonon scattering

TL;DR

This paper investigates the near-field absorption spectra of quantum well excitons considering non-Markovian phonon scattering, revealing pure dephasing effects that differ from traditional Lorentzian models.

Contribution

It introduces a non-Markovian approach to exciton-phonon interactions in disordered quantum wells using microscopic disorder states and second order Born self-energy.

Findings

Enhanced inter-peak absorption due to pure dephasing

Spectra deviate from Lorentzian lineshapes

Potential for near-field experimental measurement

Abstract

The excitonic absorption spectrum for a disordered quantum well in presence of exciton-acoustic phonon interaction is treated beyond the Markov approximation. Realistic disorder exciton states are taken from a microscopic simulation, and the deformation potential interaction is implemented. The exciton Green's function is solved with a self energy in second order Born quality. The calculated spectra differ from a superposition of Lorentzian lineshapes by enhanced inter-peak absorption. This is a manifestation of pure dephasing which should be possible to measure in near-field experiments.