Multi-Component Quantum Gases in Spin-Dependent Hexagonal Lattices

TL;DR

This paper reports the first realization of ultracold atoms in a spin-dependent hexagonal optical lattice, revealing novel magnetic and superfluid phases influenced by lattice symmetry and interactions.

Contribution

It introduces a new experimental platform for ultracold atoms in spin-dependent hexagonal lattices and demonstrates emergent magnetic and supersolid phases.

Findings

Observation of antiferromagnetic Neel order due to spin-dependent localization.

Coexistence of Mott-insulating and superfluid components forming a supersolid.

Results align with Gutzwiller mean-field theoretical predictions.

Abstract

Periodicity is one of the most fundamental structural characteristics of systems occurring in nature. The properties of these systems depend strongly on the symmetry of the underlying periodic structure. In solid state materials - for example - the static and transport properties as well as the magnetic and electronic characteristics are crucially influenced by the crystal symmetry. In this context, hexagonal structures play an extremely important role and lead to novel physics like that of carbon nanotubes or graphene. Here we report on the first realization of ultracold atoms in a spin-dependent optical lattice with hexagonal symmetry. We show how combined effects of the lattice and interactions between atoms lead to a forced antiferromagnetic N\'eel order when two spin-components localize at different lattice sites. We also demonstrate that the coexistence of two components - one Mott-insulating and the other one superfluid - leads to the formation of a forced supersolid. Our observations are consistent with theoretical predictions using Gutzwiller mean-field theory.