Condensed Matter Seminar

Fermions and bosons in natural and artificial lattices

Prof. Shan-Wen Tsai
University of California, Riverside
Tuesday, December 11
Higgins 235, 1 pm

In many strongly correlated electronic materials, both electron interactions and phonons play an important role. With the rapid advances in the field of quantum gases, it is now possible to engineer strongly correlated mixtures of fermionic and bosonic atoms in optical lattices, where new quantum phases may be accessible through the fine-tuning of atom and lattice parameters. I will present a renormalization-group method that treats both fermion-fermion interactions and fermion-boson couplings, taking into account retardation effects and the presence of multiple energy scales. It allows the study of the stability of the liquid state and its instabilities toward other complex phases. Migdal's theorem and Eliashberg's theory for superconductivity emerge naturally from this approach. I will present results for quasi-1D and 2D electronic materials, including the case of van Hove singularities, and for Bose-Fermi mixtures in artificial lattices of cold atoms.