Microscopic simulations of the coupled dynamics of cavity photons, excitons, and biexcitons
Hendrik Rose, Stefan Schumacher, Torsten Meier
TL;DR
The paper addresses how quantum light interacts with excitons and biexcitons in semiconductor nanostructures when Coulomb correlations and biexciton continua play a significant role. It introduces a fully quantized microscopic model with a single-mode cavity, a two-band tight-binding electronic structure, and Coulomb interactions, analyzed in the Heisenberg picture starting from a two-photon Fock-state for the cavity. Key findings show that coupling to the biexciton continuum induces resonance shifts and pronounced normal-mode splitting that scale with the light–matter coupling $M_0$, while weak absorption at $oldsymbol{\delta \,=\, -XX_b/2}$ signals bound biexciton excitation and unbound biexciton continua suppress photon number for $oldsymbol{\delta \, oughly\ 5~ ext{meV}}$; these effects are not captured by models limited to bound states. The work demonstrates the necessity of microscopic quantum descriptions for accurate predictions in cavity–quantum dot systems and points to future work on multi-mode fields and diverse photon statistics, with attention to truncation challenges at higher photon numbers.
Abstract
The coherent interaction between quantum light and material excitations in semiconductor nanostructures is investigated using a fully quantized microscopic approach that incorporates many-body Coulomb correlations. The simulations demonstrate that the quantum dynamics is influenced by biexciton continuum states and is highly sensitive to both the frequency of the cavity mode and the strength of the light-matter coupling.