9 papers
Excitation Spectrum of the Holstein Model
J. M. Robin
In this paper the polaron problem for the Holstein model is studied in the weak coupling limit. We use second order perturbation theory to construct renormalized electron and phono…
Metal-insulator crossover in the Boson-Fermion model in infinite dimensions
J. -M. Robin, A. Romano, J. Ranninger
The Boson-Fermion model, describing a mixture of tightly bound electron pairs and quasi-free electrons hybridized with each other via a charge exchange term, is studied in the limi…
Spectral function of the small polaron
J. M. Robin
We compute exactly both the spectral function of the electron and of the small polaron for the two site Holstein model. We find that for intermediary coupling, the small polaron is…
The Atomic Limit of the Boson-Fermion Model
T. Domanski, J. Ranninger, J. M. Robin
The Boson-Fermion model, describing a mixture of hybridized localized Bosons and itinerant Fermions on a lattice, is known to exhibit spectral properties for the Fermions which upo…
The pseudogap in underdoped high Tc superconductors in the framework of the Boson Fermion model
J. Ranninger, J. M. Robin
The question of whether the pseudogap in high cuprates is related to super conducting precursor effects or to the existence of extrinsic bosonic massive excitations is invest…
The Spin Gap in the Context of the Boson-Fermion Model for High Superconductivity
J. Ranninger, J. M. Robin
The issue of the spin gap in the magnetic susceptibility in high T_c superconductors is discussed within a scenario of a mixture of localized tightly bound electron pair…