Quantum simulation using two-electron atoms in an optical lattice

Title Quantum simulation using two-electron atoms in an optical lattice
Speaker Prof.Yoshiro Takahashi, Kyoto University
Time 10:30 AM February 19, 2019 ( Tue )
Venue CT Chang Memorial Hall 張昭鼎講堂
Contact Dr. Yu-Ju Lin(IAMS)
A system of ultracold atoms in an optical lattice is an ideal quantum simulator of a strongly correlated quantum many-body system due to the high controllability of system parameters. In this talk, I will report our recent experiments using ultracold fermions of ytterbium (Yb) in an optical lattice. 
One of the unique properties of Fermi gases of two-electron atoms is a high spin symmetry of SU(N=2I+1) of nuclear spin I, which will show novel quantum magnetism. By using a 173Yb Fermi gas with SU(N ) symmetry, we develop a technique for optically inducing a nuclear spin singlet-triplet oscillation with a spin-dependent potential gradient for measuring nearest-neighbor anti-ferromagnetic spin correlations. 

First, the straightforward comparison between the cases of SU(2) and SU(4) loaded in an optical dimerized lattice reveals the enhanced antiferromagnetic correlation for the SU(4) spin system compared with SU(2) as a consequence of a Pomeranchuk cooling effect [1]. In addition, we successfully observe the formation of nearest-neighbor antiferromagnetic spin correlations for SU(6) Fermi gases in 1D , 2D , and 3D optical lattices as well as a dimerized lattice. This work is an important step towards the observation of novel SU(N) quantum magnetism.

Other researches using Yb atoms such as the experiments towards the quantum simulation of the Kondo effect [2], non-equilibrium dynamics of Bose-Hubbard system, dissipative quantum many-body system[3], and so on will be also reported.

[1] H. Ozawa et al, PRL121, 225303(2018).
[2] K. Ono et al,  arXiv:1810.00536.
[3] T. Tomita et al, Sci. Adv. 3, e1701513 (2017).