Experimental realization of a high precision tunable hexagonal optical lattice

TL;DR

This paper demonstrates a high-precision, tunable hexagonal optical lattice setup using overlapping triangular sublattices, enabling detailed control for exploring exotic orbital physics with ultracold atoms.

Contribution

It introduces a versatile scheme for creating and precisely tuning hexagonal optical lattices by overlapping two triangular sublattices with adjustable parameters.

Findings

High-precision control of lattice geometry achieved

Method can be extended to complex lattice configurations

Facilitates exploration of novel orbital physics in ultracold atoms

Abstract

Hexagonal optical lattices offer a tunable platform to study exotic orbital physics in solid state materials. Here, we present a versatile high-precision scheme to implement a hexagonal optical lattice potential, which is engineered by overlapping two independent triangular optical sublattices generated by laser beams with slightly different wavelengths around 1064 nm. This enables us to precisely control the detailed structure of the hexagonal lattice by adjusting the relative position and the relative lattice depth of the two triangular optical sublattices. Taking advantage of the sensitive dependence of the second Bloch band on small lattice deformations, we propose a strategy to optimize the optical lattice geometry with an extremely high precision. This method can also be extended to other lattice configurations involving more than two sublattices. Our work provides the experimental requirements in the search for novel orbital physics of ultracold atoms, for example, in the flat $p$-band of the hexagonal optical lattice.