Speaker: Asst. Prof. Dr. Menderes Işkın, Koç University, İstanbul
Title: Spin-orbit coupled Fermi gases: story of topological points, rings and spheres
Date/Time: Aprl. 18 Wednesday at 10:40
Place: SUNUM Building G-111
Tea, coffee and cookies at 10:20 in SUNUM Hall.
With the ultimate success of techniques for trapping and cooling atomic gases
developed and improved gradually since the 1980's, atomic Fermi gases have
emerged as unique testing grounds for many theories of exotic matter in nature,
allowing for the creation of complex yet very accessible and controllable
many-body quantum systems. For instance, a major breakthrough was achieved with
the variation of the attractive interaction between atoms from two hyperfine
states of Lithium-6 (or Potassium-40). The tuning of interactions permits the
ground state of the system to evolve smoothly from a weak coupling
Bardeen-Cooper-Schrieffer (BCS) limit of largely overlapping Cooper pairs to a
strong coupling regime of tightly-bound bosonic molecules, which undergo
Bose-Einstein condensation (BEC).
Given that the recent experimental studies on spin-orbit coupled Bose gases
had a great success, one of the current frontiers in cold atom research is the
study of spin-orbit coupled Fermi gases. In this talk, following an overview
of earlier theoretical and experimental works on the usual BCS-BEC crossover
problem, I will present our new results for the spin-orbit coupled systems.
I will analyze both the ground state and finite temperature phase diagrams for
uniform systems . In particular, I will show that the topological structure
of the ground-state phase diagrams is quite robust against the effects of
anisotropy of the spin-orbit coupling. I will also show that the critical
condensation temperature increases considerably in the molecular BEC limit.
Depending on my timing, I may also present our very recent results on the
vortex core and edge states in these systems.