Quantum phases of low-dimensional ultra-cold atom systems

Bo-Bo Wei

Ludwig Mathey, Ashvin Vishwanath, Ehud Altman

Kyle Irwin

Ultra-cold fermionic atoms trapped in optical lattices may be a candidate for the discovery of new novel phenomena in condensed matter systems.Experiments afford the creation of virtually any lattice geometry, and physicalparameters of tight binding type lattice models can be acurately and easily tuned. Although some theoretical work has been conducted, few have used the power of the functional renormalization group method to unearth rigorous methods for determining collective many-body phases in this regime. Motivated byrecent theoretical achievements, we investigate novel condensed matter systemsinvolving interacting fermions which are engineered to be confined in differentdimensions. In this sense, we seek low energy effective theories for low-dimensional fermionic lattice systems embedded into higher dimensional lattice systems, and show how tuning physical quantities, such as the fillingor density, can have dramatic effects on the behavior of the lower dimensionalsystem.

Jasleen Lugani, K Thyagarajan, Sankalpa Ghosh

In this paper, we consider the transmission characteristics of an optical cavity loaded with ultra cold atoms in a one dimensional optical lattice at absolute zero temperature. In particular, we consider the situation when the many body quantum state of the ultra cold atoms is an insulating state with fixed number of atoms at each site, which can be either density wave (DW) or Mott insulator (MI) phase, each showing different type of discrete lattice translational symmetry. We provide a general framework of understanding the transmission spectrum from a single and two cavities/modes loaded with such insulating phases. Further, we also discuss how such a transmission spectrum changes when these insulating phases make a cross over to the superfluid (SF) phase with the changing depth of the optical lattice potential.

Kazuo Ueda, 上田 和夫

Sebastian Diehl, Andrea Micheli, Adrian Kantian +3 more