Please join us for a special AMO Seminar presented by Johannes Zeiher, Max-Planck Institute of Quantum Optics

Title: Quantum gas microscopy of Hubbard models in and out of equilibrium

Abstract: Neutral atoms trapped in optical lattices are a versatile platform to study many-body physics in and out of equilibrium.

Quantum gas microscopes provide an excellent toolbox to prepare, control and detect such systems at the level of individual atoms.
In my talk, I will present our recent work on implementing passively phase-stable square and triangular lattices for bosonic rubidium atoms.

Combining these base lattices with fine-tuned local on-site potential shifts, we realize a number of derived lattice configurations, among them Lieb and kagome lattices. After verifying the versatility of our technique via single-atom quantum walks, we study the many-body physics emerging at strong Hubbard interactions. In particular, we characterize the superfluid-to-Mott-insulator transition through a measurement of brane parity, a non-local observable derived from string correlators.

In the second part of the talk, I will focus on our recent experiments on characterizing spin transport in Heisenberg chains. Using a direct mapping between the two-component Bose-Hubbard model and the Heisenberg model, we study the relaxation of spin domain walls. Our microscopic detection sheds light on the nature of transport in such systems, which we find to fall into the celebrated Kardar-Parisi-Zhang universality class.