Quantum simulation using ultracold atoms in a non-standard optical lattice (Prof. Y. Takahashi)

In this talk, I will report our recent two quantum simulation experiments using ytterbium quantum gases loaded into non-standard optical lattices. The first one is the investigation of behaviors of ultracold atoms in an optical Lieb lattice which has a novel band structure with a Dirac cone and a flat band. In particular, a flat band is important for generating novel quantum states such as a flat band ferromagnetic state for fermions and a super-solid state for bosons. We successfully load ultracold bosons into a flat band and study the dynamics characteristic of the flat band. Another is a study of topological charge pumping of ultracold fermions in a dynamical optical super-lattice. With this setup, we can simulate a Rice-Mele model in which time-dependent potential depths and hopping strengths are introduced in a staggered form. Charge pumping is directly measured as a shift of an atom cloud. In particular, a topological nature of this charge pumping scheme is revealed by the measurements with various trajectories of system parameters.