# Multicomponent exciton gas in cuprous oxide: cooling behaviour and the role of Auger decay

## TL;DR

This paper develops a hydrodynamic model for exciton gases in cuprous oxide, analyzing cooling behavior and the impact of Auger decay, with comparisons to experimental data and alternative biexciton formation explanations.

## Contribution

It introduces a comprehensive hydrodynamic model that includes exciton interactions, finite lifetime, and Auger decay, providing new insights into exciton dynamics at ultralow temperatures.

## Key findings

- Auger decay significantly affects exciton lifetime and cooling.
- Model predictions align with experimental observations.
- Alternative biexciton formation mechanisms are also considered.

## Abstract

In this paper we present a hydrodynamic model to describe the dynamics of para- and orthoexcitons in cuprous oxide at ultralow temperatures inside a stress induced potential trap. We take into account the finite lifetime of the excitons, the excitation process and exciton-phonon as well as exciton-exciton interaction. Furthermore, we model the two-body loss mechanism assuming an Auger-like effect and compare it to an alternative explanation which relies on the formation of biexcitons. We discuss in detail the influence on the numerical results and compare the predictions to experimental data.