Strongly Interacting Atoms and Molecules in a 3D Optical Lattice

TL;DR

This paper demonstrates the creation of a strongly interacting fermionic gas in a 3D optical lattice, revealing insights into atom-molecule transitions and temperature measurement via Feshbach resonances.

Contribution

It reports the first realization of a strongly interacting quantum degenerate Fermi gas in a 3D optical lattice with controlled atom-molecule conversion.

Findings

Induced strong interactions using Feshbach resonance.

Observed transfer of atoms to higher Bloch bands.

Formed molecules and estimated atomic temperature.

Abstract

We report on the realization of a strongly interacting quantum degenerate gas of fermionic atoms in a three-dimensional optical lattice. We prepare a band-insulating state for a two-component Fermi gas with one atom per spin state per lattice site. Using a Feshbach resonance, we induce strong interactions between the atoms. When sweeping the magnetic field from the repulsive side towards the attractive side of the Feshbach resonance we induce a coupling between Bloch bands leading to a transfer of atoms from the lowest band into higher bands. Sweeping the magnetic field across the Feshbach resonance from the attractive towards the repulsive side leads to two-particle bound states and ultimately to the formation of molecules. From the fraction of formed molecules we determine the temperature of the atoms in the lattice.