Collective pairing of resonantly coupled microcavity polaritons

TL;DR

This paper explores the phases of microcavity polaritons near a bipolariton Feshbach resonance, revealing a novel molecular superfluid phase with potential experimental realization.

Contribution

It introduces the concept of a molecular superfluid phase of polaritons and provides a phase diagram with experimental signatures, expanding understanding of polariton many-body states.

Findings

Discovery of a molecular superfluid phase of polaritons.

Phase diagram including critical temperature, density, and detuning.

Potential for experimental observation of the molecular superfluid.

Abstract

We consider the possible phases of microcavity polaritons tuned near a bipolariton Feshbach resonance. We show that, as well as the regular polariton superfluid phase, a "molecular" superfluid exists, with (quasi-)long-range order only for pairs of polaritons. We describe the experimental signatures of this state. Using variational approaches we find the phase diagram (critical temperature, density and exciton-photon detuning). Unlike ultracold atoms, the molecular superfluid is not inherently unstable, and our phase diagram suggests it is attainable in current experiments.