Single-atom imaging of fermions in a quantum-gas microscope

TL;DR

This paper demonstrates the first single-site fluorescence imaging of fermionic potassium-40 atoms in an optical lattice using electromagnetically-induced-transparency cooling, enabling detailed studies of strongly correlated fermionic quantum systems.

Contribution

It introduces a novel imaging technique for fermionic atoms in optical lattices, expanding quantum simulation capabilities beyond bosonic species.

Findings

Achieved detection of 1000 fluorescence photons from a single fermionic atom in 1.5 seconds.

Maintained atoms close to the vibrational ground state during imaging.

Enabled potential studies of local entropy and defects in fermionic quantum phases.

Abstract

Single-atom-resolved detection in optical lattices using quantum-gas microscopes has enabled a new generation of experiments in the field of quantum simulation. Fluorescence imaging of individual atoms has so far been achieved for bosonic species with optical molasses cooling, whereas detection of fermionic alkaline atoms in optical lattices by this method has proven more challenging. Here we demonstrate single-site- and single-atom-resolved fluorescence imaging of fermionic potassium-40 atoms in a quantum-gas microscope setup using electromagnetically-induced-transparency cooling. We detected on average 1000 fluorescence photons from a single atom within 1.5s, while keeping it close to the vibrational ground state of the optical lattice. Our results will enable the study of strongly correlated fermionic quantum systems in optical lattices with resolution at the single-atom level, and give access to observables such as the local entropy distribution and individual defects in fermionic Mott insulators or anti-ferromagnetically ordered phases.