AMO Seminar: Ariel Sommer, Lehigh University, “Spin transport at normal-superfluid interfaces in the unitary Fermi gas”

Event time: 
Wednesday, February 15, 2023 - 11:00am to 12:00pm
Sloane Physics Laboratory SPL, Room 51 See map
217 Prospect Street
New Haven, CT 06511
Ariel Sommers, Lehigh University
Event description: 

Quantum gases of fermionic atoms provide a model system for studying the dynamics of strongly interacting fermions. The development of box trap potentials and programmable optical potentials creates a myriad of opportunities to investigate many-body systems out of equilibrium. I will discuss proposed experiments employing a multi-region trap to explore spin transport in superfluid Fermi gases. Spin-imbalanced Fermi gases exhibit coexistence of superfluid and normal phases at a first-order phase transition. A multi-region trap will allow preparation of normal and superfluid regions out of equilibrium with one another. I will describe theoretical calculations investigating particle transport across the normal-superfluid interface out of equilibrium in a phenomenological mean-field model. We find that transport into an unpolarized superfluid from a polarized normal fluid exhibits a threshold in the normal fluid polarization, analogous to the current-voltage curve of a normal-superconductor junction. However, the threshold nearly vanishes when the superfluid reaches critical polarization. Experiments on this system will explore the effects of strong correlations on transport.
Host: Nir Navon (