Tuesday, 07 February, 2012
Group Seminar LMU: Spin-Orbit Coupled Quantum Gases
Tuesday, 07.02.2012 10:00 a.m. (s.t.) in H107, Fakultät für Physik LMU
Prof. Hui Zhai, Institute for Advanced Study, Tsinghua University
In this talk I will discuss recent theoretical and experimental progresses in spin-orbit coupled Bose condensate and degenerate Fermi gases.
In the first part of this talk, I will discuss our recent theoretical works on cold atoms with Rashba-type spin-orbit coupling. For bosons with Rashba type spin-orbit coupling, we find the ground state exhibits two distinct non-trivial phases: the plane wave phase and the stripe superfluid phase. And the finite temperature thermal fluctuations can lead to an even more interesting boson paired superfluid state with half vortices. For fermions, we emphasize that Rashba spin-orbit coupling can significantly enhance the pairing strength and the superfluid transition temperature.
In the second part of this talk, I will report the collaboration with two experimental groups in China on bosons and fermions with NIST-type spin-orbit coupling. In collaboration with the experimental group in USTC, we find the dipole modes of a BEC is no longer harmonic due to the non-abelian nature of the gauge potential. We also observe a magnetization oscillation synchronized to the dipole motion due to spin-orbit coupling, as well as quantum tunneling during the dipole oscillation. In collaboration with the experimental group in Shanxi University, we have realized spin-orbit coupled Fermi gases, studied spin dephasing in Raman induced spin dynamics due to spin-orbit coupling and observed the topological change of Fermi surface as the density of Fermi gas changes.