Probing dynamical properties of Fermi-Hubbard systems with a quantum gas microscope (Prof. Waseem Bakr)
Prof. Waseem Bakr
Princeton University, New Jersey, USA
Max Planck Institute of Quantum Optics
Herbert Walther Lecture Hall
The normal state of high-temperature superconductors exhibits anomalous transport and spectral properties that are poorly understood. Cold atoms in optical lattices have been used to realize the celebrated Fermi-Hubbard model, widely believed to capture the essential physics of these materials. The recent development of fermionic quantum gas microscopes has enabled studying Hubbard systems with single-site resolution. Most studies have focused on probing equal-time spin and density correlations.
In this talk, I will report on using a microscope to
probe response functions associated with unequal-time correlations relevant for
understanding the pseudogap and strange metal regimes of Fermi-Hubbard systems.
First, I will describe the development of a technique to measure microscopic
diffusion, and hence resistivity, in doped Mott insulators. We have found that
this resistivity exhibits a linear dependence on temperature and violates the
Mott-Ioffe-Regel limit, two signatures of strange metallic behavior. Next, I will
report on the development of angle-resolved photoemission spectroscopy (ARPES)
for Hubbard systems and its application to studying pseudogap physics in an
attractive Hubbard system across the BEC-BCS crossover, setting the stage for
future studies of the pseudogap regime in repulsive Hubbard systems.