Spectral properties of the attractive Hubbard model
Physikinstitut, Universität Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
Accepted: 30 July 1998
Published online: 15 January 1999
We calculate the spectral functions, the band structure and the density of states of the 2D attractive Hubbard model in the intermediate coupling regime (i.e. the crossover regime between BCS theory and Bose-Einstein Condensation) using a grand canonical quantum Monte-Carlo approach and a maximum entropy procedure. The evolution of the spectral properties as a function of temperature is discussed. In particular, on lowering the temperature, we find a splitting of the single band present at high temperatures into several distinct branches, the number of which depends on the temperature.
PACS: 74.20.-z – Theories and models of superconducting state / 74.25.Dw – Superconductivity phase diagrams / 71.10.Fd – Lattice Fermion models (Hubbard model, etc.)
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1999