Theory of intersubband resonance fluorescence

TL;DR

This paper develops a theoretical model for the fluorescence spectrum of a strongly pumped intersubband transition in quantum wells, revealing how electron coherence influences the Mollow triplet and enabling measurement of electron coherence time.

Contribution

It introduces a modified Mollow theory accounting for many-electron effects in intersubband systems, linking fluorescence intensity to electron coherence.

Findings

Central peak intensity depends on electron coherence

The model predicts measurable coherence times via fluorescence

Modification of Mollow triplet in many-electron systems

Abstract

The fluorescence spectrum of a strongly pumped two level system is characterised by the Mollow triplet that has been observed in a variety of systems, ranging from atoms to quantum dots and superconducting qubits. We theoretically studied the fluorescence of a strongly pumped intersubband transition in a quantum well. Our results show that the many-electron nature of such a system leads to a modification of the usual Mollow theory. In particular, the intensity of the central peak in the fluorescence spectrum becomes a function of the electron coherence, allowing access to the coherence time of a two dimensional electron gas through a fluorescence intensity measurement.