Quantum simulators based on the global collective light-matter interaction

TL;DR

This paper demonstrates how coupling ultracold atoms in optical lattices to quantized cavity modes creates novel quantum phases with both short- and long-range interactions, enabling advanced quantum simulation of complex many-body systems.

Contribution

It introduces a method to engineer finite-range interactions via spatial structuring of global light-matter coupling, offering an alternative to existing quantum simulation platforms.

Findings

Supports non-trivial superfluid, dimer, trimer, and supersolid phases.

Shows tunability of effective interaction length and geometry.

Provides a versatile setup for exploring strongly correlated physics.

Abstract

We show that coupling ultracold atoms in optical lattices to quantized modes of an optical cavity leads to quantum phases of matter, which at the same time posses properties of systems with both short- and long-range interactions. This opens perspectives for novel quantum simulators of finite-range interacting systems, even though the light-induced interaction is global (i.e. infinitely long range). This is achieved by spatial structuring of the global light-matter coupling at a microscopic scale. Such simulators can directly benefit from the collective enhancement of the global light-matter interaction and constitute an alternative to standard approaches using Rydberg atoms or polar molecules. The system in the steady state of light induces effective many-body interactions that change the landscape of the phase diagram of the typical Bose-Hubbard model. Therefore, the system can support non-trivial superfluid states, bosonic dimer, trimers, etc. states and supersolid phases depending on the choice of the wavelength and pattern of the light with respect to the classical optical lattice potential. We find that by carefully choosing the system parameters one can investigate diverse strongly correlated physics with the same setup, i.e., modifying the geometry of light beams. In particular, we present the interplay between the density and bond (or matter-wave coherence) interactions. We show how to tune the effective interaction length in such a hybrid system with both short-range and global interactions.