Tuesday, 03 July, 2012
Group seminar LMU: Spin dynamics of ultracold Fermions in optical lattices
Tuesday, 03.07.2012 10:00 a.m. (s.t.) in H107, Fakultät für Physik, LMU
Christoph Becker, Institute for Laserphysics, Univ. of Hamburg
Spin dynamics of ultracold Fermions in optical lattices
Quantum gases in optical lattices offer a wide range of applications for quantum simulation due to the full control over lattice and interaction parameters as well as the internal atomic degrees of freedom.
I will report on spin dynamics of different interacting spin-mixtures of fermionic potassium atoms loaded into an optical lattice. In contrast to electrons with spin-1/2, the higher spin of 40K has important consequences for the local as well as the global properties of the system. The effective spin dimensionality of the system can be tuned by varying the magnetic field and choosing particular intital states. In this way the complexity of the observed spin dynamics can be varied. We compare our data to a simplified two-particle model which is in very good agreement with the observations.
Beyond these pure onsite effects we observe that local spin oscillations generically lead to a global instability of the initial band insulating state for high spin atoms.
Our results open new perspectives to study magnetism of fermionic lattice systems beyond conventional spin-1/2 systems.