title: Gap formation and soft phonon mode in the Holstein model.
abstract: We investigate electron-phonon coupling in many-electron systems using the dynamical mean-field theory in combination with the numerical renormalization group. This nonperturbative method reveals significant precursor effects to the gap formation at intermediate coupling strengths. The emergence of a soft phonon mode and very strong lattice fluctuations can be understood in terms of Kondo-like physics due to the development of a double-well structure in the effective potential for the ions.
authors.affiliation: Department of Mathematics, Imperial College, London SW7 2BZ, United Kingdom. d.meyer@ic.ac.uk
authors.forename: D
authors.initials: D
authors.lastname: Meyer
authors.forename: A C
authors.initials: AC
authors.lastname: Hewson
authors.forename: R
authors.initials: R
authors.lastname: Bulla