Ultracold Atoms in Optical Lattices: Quantum Simulation of the Fermi-Hubbard Model

We observe long-range “trilobite-like” states of ultracold 85Rb2 molecules in which a novel form of chemical bonding occurs: an ultracold ground state atom is bound by the attraction of the Rydberg electron, with its Rydberg electronic wavefunction in np Rydberg atomic levels with n = 7-12 [1]. Unlike earlier work by others at much higher n formed by photoassociation, our observations involve bound-bound transitions excited in the ultraviolet where the upper state autoionizes to produce Rb2+, which is detected by time-of-flight mass spectroscopy. The lower state in these observations is primarily v”= 35, J”= 1 of the metastable a 3Σu+ state. The important upper electronic states are calculated to be a 3Πg and a 3Σg+ state, each with a deep short range well and a shallow long range well and an intermediate barrier between the two wells [2]. Recently we have improved our resolution by over a factor of 100 and now see well-defined structure in lines that were unresolved in ref. [1]. Our latest data and analysis will be discussed. *Work in conjunction with R. Carollo, Y. Bruneau, E. Eyler, and P. Gould, supported by NSF and AFOSR [1] M.A. Bellos, et al., Phys. Rev. Lett. 111, 053001 (2013). [2] M.A. Bellos, et al., Phys. Rev. A 87, 012508 (2013). Faculty Interview Physics Department Ultracold Atoms in Optical Lattices: Quantum Simulation of the Fermi-Hubbard Model Dr. Russell Hart Rice University High Resolution Spectroscopy of Long-Range “Trilobite-like” States of Ultracold Rb2 Molecules* William C. Stwalley, Physics Department, UConn April 22, 2015 SERC # 408, 3pm Refreshments served at 2.45pm