"Strongly Interacting Fermi Gases under the Microscope"

Mon, 04/10/2017 - 4:15pm

Please join us Monday, April 10, 2017, as Martin Zwierlein of MIT gives his colloquium:

"Strongly Interacting Fermi Gases under the Microscope"

Strongly interacting fermions govern the physics of e.g. high-temperature superconductors, nuclear matter and neutron stars. The interplay of the Pauli principle with strong interactions can give rise to exotic properties that we do not even understand at a qualitative level. In recent years, ultracold Fermi gases of atoms have emerged as a pristine platform for the creation and study of strongly interacting systems of fermions. Near Feshbach resonances, such gases display superfluidity at 17% of the Fermi temperature. Scaled to the density of electrons in solids, this corresponds to superfluidity far above room temperature. Confined in optical lattices, fermionic atoms realize the Fermi-Hubbard model, believed to capture the essence of cuprate high-temperature superconductors. In recent experiments on two-dimensional Fermi gases under a microscope, we observe metallic, Mott insulating and band insulating states with single-site, single-atom resolution. The microscope allows for the site-resolved detection of charge and spin correlations, revealing the famous Pauli and correlation hole for low and intermediate lattice fillings, and correlated doublon-hole pairs near half filling. These correlations should play an important role for transport in the Fermi-Hubbard model.

About the speaker

Martin Zwierlein studied physics at the University of Bonn and at the Ecole Normale Supérieure in Paris. His doctoral thesis in the group of Wolfgang Ketterle at MIT focused on the observation of superfluidity in ultracold fermionic gases, a novel form of strongly interacting matter. After a postdoctoral stay at the University of Mainz in the group of Immanuel Bloch, he joined the MIT physics department in 2007. His group is using ultracold atomic gases to study models of many-body physics relevant for condensed matter, nuclear and astrophysics. He and his team recently observed Fermi polarons and the quantum limit of diffusion in strongly interacting Fermi gases. His awards include the Klung-Wilhelmy-Weberbank-Prize, Freie Universität Berlin (2007), Young Investigator Awards from the Air Force Office of Scientific Research, the Office of Naval Research and DARPA (2010), a David and Lucile Packard Fellowship (2010) and a Presidential Early Career Award for Scientists and Engineers (2010).