Spontaneous patterns in coherently driven polariton microcavities

TL;DR

This paper investigates how driven polariton microcavities spontaneously form various spatial patterns due to instabilities, with control over pattern evolution, using stability analysis and numerical simulations.

Contribution

It introduces a detailed analysis of pattern formation in coherently driven polariton microcavities, highlighting the role of two-pump versus single-pump regimes and symmetry breaking.

Findings

Stripe and chequerboard patterns dominate in two-pump instabilities.

Hexagonal patterns are prevalent in single-pump scenarios.

Pattern evolution can be controlled through system parameters.

Abstract

We consider a polariton microcavity resonantly driven by two external lasers which simultaneously pump both lower and upper polariton branches at normal incidence. In this setup, we study the occurrence of instabilities of the pump-only solutions towards the spontaneous formation of patterns. Their appearance is a consequence of the spontaneous symmetry breaking of translational and rotational invariance due to interaction induced parametric scattering. We observe the evolution between diverse patterns which can be classified as single-pump, where parametric scattering occurs at the same energy as one of the pumps, and as two-pump, where scattering occurs at a different energy. For two-pump instabilities, stripe and chequerboard patterns become the dominant steady-state solutions because cubic parametric scattering processes are forbidden. This contrasts with the single-pump case, where hexagonal patterns are the most common arrangements. We study the possibility of controlling the evolution between different patterns. Our results are obtained within a linear stability analysis and are confirmed by finite size full numerical calculations.