Dartmouth Events

Physics & Astronomy Virtual Quantum Nano Seminar-Kevin Wright, Dartmouth College

Title: "Persistent Currents in Rings of Ultracold Fermionic Atoms"

Thursday, May 6, 2021
4:00pm – 5:00pm
Zoom: Email for link and password.
Intended Audience(s): Public
Categories: Lectures & Seminars
Abstract: Experiments in cylindrical, toroidal, and more exotic geometries have been critical to progress in understanding quantum materials and their transport properties. Ultracold quantum gases have provided many important insights in the study of quantum phases of matter, and many notable experiments involving superfluid ``circuits'' of ultracold bosons have been conducted during the past decade. Construction of equivalent fermionic systems has been delayed by serious technical challenges, but my lab at Dartmouth recently achieved this longstanding experimental goal. I will describe several recent experiments in which we manipulated a quantum degenerate Fermi gas of lithium atoms confined to a narrow ring. One key result was the observation of quantized superfluid flow, confirming that "persistent current" states can be long-lived in the molecular BEC, unitary, and BCS superfluid phases. We also observed the threshold for decay of the current in the BCS limit and investigated the reappearance of quantized currents after a circulating BCS superfluid is briefly quenched into the normal phase. The most exciting aspect of these results is the evidence they provide that more ambitious experiments are possible, and I will conclude by describing planned experiments with spin-imbalanced Fermi gases, quasi-1D fermionic rings, coupled rings, and ring lattices.
For more information, contact:
Tressena Manning

Events are free and open to the public unless otherwise noted.