# Emergence and stability of spontaneous vortex lattices in exciton-polariton condensates

## TL;DR

This paper theoretically investigates how the decay rate of the exciton reservoir affects the formation and stability of vortex lattices in exciton-polariton Bose-Einstein condensates, highlighting the role of external angular momentum in stabilizing these structures.

## Contribution

It introduces a theoretical model considering reservoir decay rates and demonstrates how external angular momentum can stabilize vortex lattices in open quantum systems.

## Key findings

- Decreasing reservoir decay rate reduces vortex number and destabilizes lattices.
- External angular momentum can stabilize vortex lattice structures.
- Reservoir decay rate influences vortex formation in polariton condensates.

## Abstract

The spontaneous formation of lattice structure of quantized vortices is a characteristic feature of superfluidity in closed systems under thermal equilibrium. In exciton-polariton Bose-Einstein condensate, which is a typical example of macroscopic quantum state in open systems, spontaneous vortex lattices have also been proposed by not yet observed. Here, we take into account the finite decay rate of exciton reservoir, and theoretically investigate the vortex structures in circularly pumped polariton Bose-Einstein condensate. Our results show that a decreasing reservoir decay rate can reduce the number of vortices and destabilize the lattice structure, hence is unfavorable to the formation and observation of vortex lattices. These detrimental effects can be prevailed by applying an external angular momentum.