Dresden 2026 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

HL: Fachverband Halbleiterphysik

HL 55: Quantum Dots and Wires: (Single) Photonics

HL 55.3: Vortrag

Freitag, 13. März 2026, 10:00–10:15, POT/0251

Beyond-Dipole Radiative Lifetimes of Excitons and Biexcitons in GaAs/AlGaAs Quantum Dots — •Petr Klenovský — Masaryk University, Brno, Czech Republic — Czech Metrology Institute, Brno, Czech Republic

Semiconductor quantum dots are promising sources of on-demand single and entangled photons, but a quantitative microscopic description of their radiative lifetimes remains challenging. We theoretically investigate Coulomb-correlated multi-particle states (X⁰, X^±, XX) in weakly confining GaAs/AlGaAs quantum dots using an 8-band k·p model combined with continuum elasticity and configuration interaction (CI). Polarization-resolved oscillator strengths and radiative rates are computed both in the dipole approximation and in a quasi-electrostatic beyond-dipole formulation based on a Poisson reformulation of the dyadic Green tensor. For the dots studied, the beyond-dipole treatment yields exciton and biexciton lifetimes in quantitative agreement with experiment. We further analyze electric-field tuning of the multi-particle spectrum and the resulting indistinguishability, characterized by P = τ^X / (τ^X + τ^XX), and discuss the sensitivity to CI-basis size and to electron-electron and hole-hole exchange.

Keywords: Weakly confining GaAs/AlGaAs quantum dots; Correlated excitons, trions, and biexcitons; 8-band k·p and configuration interaction; Beyond-dipole (Poisson-based) radiative lifetimes; Tuning of photon indistinguishability