Photon Devil's staircase: photon long-range repulsive interaction in lattices of coupled resonators with Rydberg atoms

TL;DR

This paper proposes a method to induce strong long-range repulsive interactions between photons in coupled resonator lattices with Rydberg atoms, leading to novel quantum phases such as the photon Devil's staircase and photon-frozen solid phase.

Contribution

It derives a mechanism for strong photon long-range repulsion using Rydberg atoms in cavity lattices and predicts new quantum phases resulting from these interactions.

Findings

Prediction of photon Devil's staircase phase without photon hopping.

Identification of a photon-floating solid phase with photon hopping.

Introduction of a photon-frozen solid phase at large chemical potential.

Abstract

The realization of strong coherent interactions between individual photons is a long-standing goal in science and engineering. In this report, based on recent experimental setups, we derive a strong photon long-range repulsive interaction, by controlling the van der Waals repulsive force between Cesium Rydberg atoms located inside different cavities in extended Jaynes-Cummings-Hubbard Lattices. We also find novel quantum phases induced by this photon long-range repulsive interaction. For example, without photon hopping, a photon Devil's staircase, induced by the breaking of long-range translation symmetry, can emerge. If photon hopping occurs, we predict a photon-floating solid phase, due to the motion of particle-and hole-like defects. More importantly, for a large chemical potential in the resonant case, the photon hopping can be frozen even if the hopping term exists. We call this new phase the photon-frozen solid phase. In experiments, these predicted phases could be detedted by measuring the number of polaritons via resonance fluorescence.