Reanalysis of experimental determinations of polariton-polariton interactions in microcavities

TL;DR

This paper reviews experimental measurements of polariton-polariton interactions in microcavities, compares results, and provides new theoretical insights, revealing that the interaction strength is lower than earlier estimates but still exceeds theoretical predictions.

Contribution

It offers a comprehensive comparison of experimental data and introduces a new theoretical analysis to refine the interaction parameter in microcavity polaritons.

Findings

Corrected interaction parameter is lower than previous reports.

Measurements sensitive to scattering rates are crucial for calibration.

Interaction strength remains higher than theoretical predictions.

Abstract

The polariton-polariton interaction strength is an important parameter for all kinds of applications using the nonlinear properties of polaritons, such as optical switching and single-photon blockade devices. In this paper, we review and compare the results of a series of experiments on polariton-polariton interactions in GaAs/Al$_x$Ga$_{-1x}$As microcavity polariton structures, and present new theoretical analysis of these experiments. We show that not just the energy shift of the spectral lines, but also the results of measurements sensitive to the polariton scattering rate are important for the calibration of the interaction parameter at low excitation density. We find that when adjustments are made to correct for new understanding of the experiments, the value of the interaction parameter at low density is lower than previous reported, but still significantly higher than theoretically predicted.