Microscopy of Ultracold Fermions in Optical Lattices

TL;DR

This paper reviews recent experimental advances in studying the Fermi-Hubbard model with ultracold fermions in optical lattices, highlighting site-resolved measurements, quasiparticle imaging, and exploration of novel lattice geometries.

Contribution

It summarizes cutting-edge quantum gas microscope experiments and new phases in Hubbard systems with complex geometries and interactions.

Findings

Site-resolved charge and spin correlations measured

Direct imaging of polaronic quasiparticles achieved

New phases stabilized by long-range interactions

Abstract

These lecture notes review recent progress in studying the Fermi-Hubbard model using ultracold gases in optical lattices. We focus on results from quantum gas microscope experiments that have allowed site-resolved measurements of charge and spin correlations in half-filled and doped Hubbard systems, as well as direct imaging of various types of polaronic quasiparticles. We also review experiments exploring dynamical properties of the Hubbard model through transport and spectroscopy. Moving beyond the plain-vanilla square-lattice Hubbard model, we present more recent work exploring Hubbard systems with novel lattice geometries and long-range interactions that stabilize new phases. Finally, we discuss the realization of entropy distribution protocols to cool these systems to ultralow temperatures where comparison to unbiased numerics is no longer possible.