Quantum Institute: Visitor Schedule

The Quantum Lunch is regularly held on Thursdays in the Theoretical Division Conference Room, TA-3, Building 123, Room 121.
For more information, contact Diego Dalvit.
To add your name to the Quantum Lunch email list, contact Charlotte Lehman

Thursday, March 11, 2010
12:30 PM - 2:00 PM

Speaker: Chih-Chun Chien (T-4)

Technical Host: Michael Zwolak

TOPIC: Quantum Many-Body Phases in Ultra-Cold Atoms: Interactions, Lattices, Population-Imbalance, Dynamics

Abstract
I will review some interesting quantum many-body phases in ultra-cold atoms, including fermions and bosons. In trapped fermions, the interactions can be attractive or repulsive. On the attractive side, fermions form Cooper pairs and the superfluid phase exhibits a BCS-Bose Einstein condensation (BEC) crossover as the attraction increases. One the repulsive side, a possible ferromagnetic phase emerges as the system crosses Stoner instability. For trapped bosons, repulsive interactions results in BEC while attractive interactions cause instabilities. When ultra-cold atoms are loaded into optical lattices, both bosons and fermions can exhibit a Mott insulator phase on the strongly repulsive side. The simple BCS-BEC crossover of fermions, however, is interrupted in lattices due to the emergence of localized states. Trapping different atoms in different lattices allows controlled interactions and read-out of information. Population-Imbalanced (polarized) fermions are of particular interest because they can exhibit exotic phases such as polarized superfluid, polarized Fermi-liquid, polaron-like liquid, and maybe FFLO phase. When temperature or interaction strength changes rapidly, dynamical phenomena such as a quench of excited states have been demonstrated in bosons and they can be studied in fermions as well.