# Exciton Polaritons in a Two-Dimensional Lieb Lattice with Spin-Orbit Coupling

## TL;DR

This paper investigates exciton-polaritons in a 2D Lieb lattice, revealing flat bands, bosonic condensation, and spin-orbit effects, demonstrating the potential for simulating complex quantum Hamiltonians.

## Contribution

It introduces a system with flat bands and spin-orbit coupling in a polariton lattice, enabling exploration of novel quantum phenomena.

## Key findings

- Observation of two flat bands from $S$ and $P_{x,y}$ orbitals
- Bosonic condensation occurs in the flat bands
- Emission patterns exhibit pseudospin textures

## Abstract

We study exciton-polaritons in a two-dimensional Lieb lattice of micropillars. The energy spectrum of the system features two flat bands formed from $S$ and $P_{x,y}$ photonic orbitals, into which we trigger bosonic condensation under high power excitation. The symmetry of the orbital wave functions combined with photonic spin-orbit coupling gives rise to emission patterns with pseudospin texture in the flat band condensates. Our work shows the potential of polariton lattices for emulating flat band Hamiltonians with spin-orbit coupling, orbital degrees of freedom and interactions.