Dynamics of quantum dot superradiance

TL;DR

This paper analyzes the dynamical stages of superradiance in quantum dot assemblies, detailing how coherence develops and decays through various phases, including pulsing superradiance under continuous pumping.

Contribution

It provides a detailed theoretical analysis of the multiple stages of quantum dot superradiance, including new insights into pulsing superradiance with continuous pumping.

Findings

Identification of multiple evolution stages of superradiance

Description of conditions for pulsing superradiance

Analysis of coherence development and decay

Abstract

The possibility of realizing the superradiant regime of electromagnetic emission by the assembly of quantum dots is considered. The overall dynamical process is analyzed in detail. It is shown that there can occur several qualitatively different stages of evolution. The process starts with dipolar waves triggering the spontaneous radiation of individual dots. This corresponds to the fluctuation stage, when the dots are not yet noticeably correlated with each other. The second is the quantum stage, when the dot interactions through the common radiation field become more important, but the coherence is not yet developed. The third is the coherent stage, when the dots radiate coherently, emitting a superradiant pulse. After the superradiant pulse, the system of dots relaxes to an incoherent state in the relaxation stage. If there is no external permanent pumping, or the effective dot interactions are weak, the system tends to a stationary state during the last stationary stage, when coherence dies out to a low, practically negligible, level. In the case of permanent pumping, there exists the sixth stage of pulsing superradiance, when the system of dots emits separate coherent pulses.