School of Physics Colloquium

Optically-trapped, ultra-cold gases of spin ½-up and spin ½-down ⁶Li atoms enable “designer” interactions, offering a versatile environment for simulating exotic quantum systems that span a vast range of energy. A strongly interacting gas is a scale-invariant, nearly perfect hydrodynamic system with universal transport coefficients, enabling parameter-free comparison with predictions, where there is currently some tension.  I will discuss our latest measurements in a “box” potential, where these coefficients are directly extracted from the time-dependent response of a cloud to small perturbations. Then I will discuss measurements of information scrambling in the very weakly interacting regime, where the cloud behaves as a large spin lattice in energy space, with effective long-range interactions.

Bio:

John E. Thomas received his B. S. degree in Physics at MIT in 1973 and his Ph. D. in Physics at MIT in 1979. John joined the Physics Department at Duke University in 1986 and was named the Fritz London Distinguished Professor in 2004. In 2011, John received the Jessie Beams Award for Research from SESAPS and moved his research group (JETlab) to North Carolina State University, where he is currently the John S. Risley Distinguished Professor of Physics. John is a Fellow of the American Physical Society, a member of the Optical Society of America and a Fellow of the American Association for the Advancement of Science. In 2018, he received the APS Davisson-Germer Prize for his research on unitary Fermi gases.