Atom-Molecule Superradiance and Entanglement with Cavity-Mediated Three-Body Interactions

TL;DR

This paper proposes a scheme to generate atom-molecule superradiance with cavity-mediated three-body interactions, revealing a phase transition characterized by photon-matter entanglement and bosonic enhancement.

Contribution

It introduces a novel experimental setup for creating biatomic molecules and demonstrates long-range three-body interactions leading to superradiance and symmetry breaking.

Findings

Emergence of a self-organized square lattice phase for molecular condensate.

Observation of bosonic enhancement with cubic scaling of photon number.

Strong photon-matter entanglement characterizes the superradiant phase transition.

Abstract

Ultracold atoms coupled to optical cavities offer a powerful platform for studying strongly correlated many-body physics. Here, we propose an experimental scheme for creating biatomic molecules via cavity-enhanced photoassociation from an atomic condensate. This setup realizes long-range three-body interactions mediated by tripartite cavity-atom-molecule coupling. Beyond a critical pump strength, a self-organized square lattice phase for molecular condensate emerges, resulting in hybrid atom-molecule superradiance with spontaneous $U(1)$ symmetry breaking. Distinct from previously observed ultracold bosonic (fermionic) atomic superradiance, our findings demonstrate bosonic enhancement characterized by a cubic scaling of steady-state photon number with total atom number. Additionally, strong photon-matter entanglement is shown to effectively characterize superradiant quantum phase transition. Our findings deepen the understanding of quantum superchemistry and exotic many-body nonequilibrium dynamics in cavity-coupled quantum gases.