Tuning the lasing threshold of quantum well exciton-polaritons under a magnetic field in Faraday geometry: a theoretical study

TL;DR

This theoretical study explores how applying a magnetic field in Faraday geometry influences the lasing threshold of quantum well exciton-polaritons, revealing ways to control polariton condensation and laser performance.

Contribution

It provides a theoretical analysis of magnetic field effects on exciton-polariton lasing thresholds, highlighting the role of relaxation kinetics and pump energy in threshold modulation.

Findings

Magnetic field delays lasing threshold at low pump energies.

High pump energy and magnetic field lower the lasing threshold.

Increased magnetic field and pump energy enhance relaxation and polariton condensation.

Abstract

Polariton lasing is a promising phenomenon with potential applications in next-generation lasers that operate without the need for population inversion. Applying a perpendicular magnetic field to a quantum well (QW) significantly alters the properties of exciton-polaritons. In this theoretical study, we investigate how the lasing threshold of QW exciton-polaritons depends on the magnetic field. By modifying the exciton's effective mass and Rabi splitting, the magnetic field induces notable changes in the relaxation kinetics, which directly affect the lasing threshold. For low-energy pumping, an increase in the magnetic field delays the lasing threshold, while for high-energy pumping, the threshold is reached at much lower pump intensities. Furthermore, increasing both the pump energy and the magnetic field enhances relaxation efficiency, leading to a substantially larger number of condensed polaritons. Our result gives insights into the modulation of exciton-polariton condensation through magnetic fields, with potential implications for the design of low-threshold polariton lasers.