Spontaneous mirror-symmetry breaking in a photonic molecule

TL;DR

This paper demonstrates spontaneous mirror-symmetry breaking in a coupled photonic crystal nanolaser system, providing experimental evidence and exploring potential applications in optical switching and quantum devices.

Contribution

The first experimental demonstration of mirror-symmetry breaking in a photonic molecule using nanolasers, with insights into its potential for integrated optical and quantum technologies.

Findings

Mirror-symmetry breaking observed via pitchfork bifurcation.

Localized states can be switched with short pulses.

Transitions predicted with few intracavity photons.

Abstract

Multi-cavity photonic systems, known as photonic molecules (PMs), are ideal multi-well potential building blocks for advanced quantum and nonlinear optics. A key phenomenon arising in double well potentials is the spontaneous breaking of the inversion symmetry, i.e. a transition from a delocalized to two localized states in the wells, which are mirror images of each other. Although few theoretical studies have addressed mirror-symmetry breaking in micro and nanophotonic systems, no experimental evidence has been reported to date. Thanks to the potential barrier engineering implemented here, we demonstrate spontaneous mirror-symmetry breaking through a pitchfork bifurcation in a PM composed of two coupled photonic crystal nanolasers. Coexistence of localized states is shown by switching them with short pulses. This offers exciting prospects for the realization of ultra-compact, integrated, scalable optical flip-flops based on spontaneous symmetry breaking. Furthermore, we predict such transitions with few intracavity photons for future devices with strong quantum correlations.