Three-body interactions with cold polar molecules

TL;DR

This paper demonstrates how microwave-driven polar molecules can naturally exhibit strong three-body interactions, with controllable two-body interactions, enabling new quantum simulation possibilities in optical lattices.

Contribution

It introduces a systematic derivation of effective three-body interaction potentials in polar molecules, enabling the realization of Hubbard models with dominant three-body interactions.

Findings

Polar molecules can be engineered to have strong three-body interactions.

The derived models show phases dominated by three-body interactions.

Potential for simulating complex quantum many-body systems.

Abstract

We show that polar molecules driven by microwave fields give naturally rise to strong three-body interactions, while the two-particle interaction can be independently controlled and even switched off. The derivation of these effective interaction potentials is based on a microscopic understanding of the underlying molecular physics, and follows from a well controlled and systematic expansion into many-body interaction terms. For molecules trapped in an optical lattice, we show that these interaction potentials give rise to Hubbard models with strong nearest-neighbor two-body and three-body interaction. As an illustration, we study the one-dimensional Bose-Hubbard model with dominant three-body interaction and derive its phase diagram.