Frustrated quantum antiferromagnetism with ultracold bosons in a triangular lattice

TL;DR

This paper proposes a method to realize an anisotropic triangular-lattice Bose-Hubbard model with ultracold atoms, enabling experimental exploration of frustrated antiferromagnetism and quantum spin liquid phases at feasible temperatures.

Contribution

It introduces a novel experimental setup using dressed ultracold atoms to simulate frustrated quantum magnetic models on a triangular lattice.

Findings

Model exhibits frustrated antiferromagnetism at feasible temperatures

Interpolates between classical rotor and quantum spin-1/2 XY models

Enables experimental study of gapped spin liquid phases

Abstract

We propose to realize the anisotropic triangular-lattice Bose-Hubbard model with positive tunneling matrix elements by using ultracold atoms in an optical lattice dressed by a fast lattice oscillation. This model exhibits frustrated antiferromagnetism at experimentally feasible temperatures; it interpolates between a classical rotor model for weak interaction, and a quantum spin-1/2 $XY$-model in the limit of hard-core bosons. This allows to explore experimentally gapped spin liquid phases predicted recently [Schmied et al., New J. Phys. {\bf 10}, 045017 (2008)].