Theory of Polaron Resonance in Quantum Dots and Quantum-Dot Molecules

TL;DR

This paper develops a theoretical model describing exciton-phonon interactions in quantum dots and molecules, explaining observed temperature-dependent decay anomalies and suggesting potential for quantum information applications.

Contribution

It introduces a new theory of polaron resonance in quantum dots and molecules, explaining exciton-phonon coupling effects and their impact on quantum state decay.

Findings

Resonant exciton-phonon interactions cause Rabi oscillations.

Temperature influences the amplitude and frequency of exciton oscillations.

The theory explains recent experimental decay anomalies in quantum-dot molecules.

Abstract

The theory of exciton coupling to photons and LO phonons in quantum dots (QDs) and quantum-dot molecules (QDMs) is presented. Resonant-round trips of the exciton between the ground (bright) and excited (dark or bright) states mediated by the LO-phonon alter the decay time and yield the Rabi oscillation. The initial distributions of the population in the ground and the excited states dominate the oscillating amplitude and frequency. This property provides a detectable signature to the information stored in a qubit made from QD or QDM for a wide range of temperature T. Our results presented herein provide an explanation to the anomaly on T-dependent decay in self-assembled InGaAs/GaAs QDMs recently reported by experiment.