Microscopic theory of polariton-polariton interactions

TL;DR

This paper presents a comprehensive microscopic theory for polariton-polariton interactions, predicting enhanced interaction strengths due to cavity coupling and proposing experimental validation methods.

Contribution

It introduces a general Born-Oppenheimer theoretical framework for polariton interactions applicable to various dimensions and polariton types, extending beyond previous models.

Findings

Interaction strength is significantly enhanced by strong cavity coupling.

The theory predicts novel scaling laws for polariton interactions.

Suggestions for experimental validation and observing polariton blockade are provided.

Abstract

We develop a comprehensive theoretical model for the interaction strength between a pair of exciton-polaritons in microcavity devices. Ab initio numerical calculations for dipolar polaritons in one dimension are used as a starting point to build a Born-Oppenheimer theory that generally applies to generic -- dipolar or non-dipolar polaritons -- in both one and two dimensions. This theory anticipates that the strong coupling to the cavity mode leads to a drastic enhancement of the polariton interactions as compared to bare excitons, and predicts unexpected scaling laws in the interaction strength as a function of system parameters. Comparisons with available experimental data are drawn, and specific suggestions to validate it with new experiments are made. Promising strategies towards the observation of a strong polariton blockade regime are finally sketched.