Site-resolved imaging of ultracold fermions in a triangular-lattice quantum gas microscope

TL;DR

This paper reports the first site-resolved imaging of ultracold fermionic atoms in a triangular optical lattice, enabling studies of frustrated Hubbard models and exotic quantum phenomena.

Contribution

It introduces a novel quantum gas microscope for fermions in a triangular lattice, achieving high-resolution imaging and paving the way for exploring frustrated quantum systems.

Findings

Achieved ~98% imaging fidelity of single fermionic atoms.

Successfully resolved individual atoms in a triangular lattice.

Established a platform for studying spin correlations and quantum dynamics.

Abstract

Quantum gas microscopes have expanded the capabilities of quantum simulation of Hubbard models by enabling the study of spatial spin and density correlations in square lattices. However, quantum gas microscopes have not been realized for fermionic atoms in frustrated geometries. Here, we demonstrate the single-atom resolved imaging of ultracold fermionic $^{6}$Li atoms in a triangular optical lattice with a lattice constant of 1003 nm. The optical lattice is formed by a recycled narrow-linewidth, high-power laser combined with a light sheet to allow for Raman sideband cooling on the $D_1$ line. We optically resolve single atoms on individual lattice sites using a high-resolution objective to collect scattered photons while cooling them close to the two-dimensional ground vibrational level in each lattice site. By reconstructing the lattice occupation, we measure an imaging fidelity of ~98%. Our new triangular lattice microscope platform for fermions clears the path for studying spin-spin correlations, entanglement and dynamics of geometrically frustrated Hubbard systems which are expected to exhibit exotic emergent phenomena including spin liquids and kinetic frustration.