# Spontaneous topological transitions in a honeycomb lattice of exciton-polariton condensates due to spin bifurcations

## TL;DR

This paper theoretically investigates a honeycomb lattice of exciton-polariton condensates, revealing how varying parameters induce topological phase transitions and diverse magnetic-like orderings in the system.

## Contribution

It introduces a model of polaritonic graphene showing spontaneous topological transitions driven by spin bifurcations, a novel insight into polariton lattice phase behavior.

## Key findings

- Identification of ferromagnetic, antiferromagnetic, and valence bond phases.
- Demonstration of topological order emergence during phase transitions.
- Dependence of phases on pump intensity and coupling strength.

## Abstract

We theoretically explore nonresonantly pumped polaritonic graphene, a system consisting of a honeycomb lattice of micropillars in the regime of strong light-matter coupling. We demonstrate that, depending on the parameters of the structure, such as intensity of the pump and coupling strength between the pillars, the system shows rich variety of macroscopic ordering, including analogs of ferromagnetic, antiferromagnetic, and resonant valence bond phases. Transitions between these phases are associated with dramatic reshaping of the spectrum of the system connected with spontaneous appearance of topological order.