title: Effective doublon and hole temperatures in the photo-doped dynamic Hubbard model.
abstract: Hirsch's dynamic Hubbard model describes the effect of orbital expansion with occupancy by coupling the doublon operator to an auxiliary boson. In the Mott insulating phase, empty sites (holes) and doubly occupied orbitals (doublons) become charge carriers on top of the half-filled background. We use the nonequilibrium dynamical mean field method to study the properties of photo-doped doublons and holes in this model in the strongly correlated regime. In particular, we discuss how photodoping leads to doublon and hole populations with different effective temperatures, and we analyze the relaxation behavior as a function of the boson coupling and boson energy. In the polaronic regime, the nontrivial energy exchange between doublons, holes, and bosons can result in a negative temperature distribution for the holes.
authors.affiliation: Department of Physics, University of Fribourg , 1700 Fribourg, Switzerland.
authors.forename: Philipp
authors.initials: P
authors.lastname: Werner
authors.affiliation: Department of Physics, University of Hamburg , Hamburg 20148, Germany ; Center for Free-Electron Laser Science, Hamburg 22761, Germany; and Max Planck Institute for the Structure and Dynamics of Matter, Hamburg 22761, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Eckstein