---

Orbital physics in excited bands of optical lattices After numerous advances in manipulation and detection techniques, cold atoms in optical lattices have become a primary candidate for studies of mesoscopic quantum phenomena. The possibility of accessing both the weakly and strongly correlated regimes, allows for investigation of a variety of phenomena which include quantum phase transitions. After a brief introduction to the field of cold atoms, here we will explore the physics in excited bands of optical lattices - the p band. Due to an additional orbital degree of freedom, the physics in the p band is qualitatively different from the physics of the usual systems in the ground band. We will start by defining these orbital states and describing mean field properties of the system, with particular emphasis on the condensation (in the p band) of a confined system. We will then move to the strongly correlated regime to show that under specific circumstances, the physics of bosons in the p band can be described by the spin-1/2 quantum XYZ Heisenberg model in an external field, that is one of the paradigmatic models in the study of quantum magnetism.

---

Fernanda Pinheiro, Stockholm University and Nordita
Institute for Genetics, Zülpicher Str. 47a, New Seminar Room 0.46, ground floor
Contact: not specified