vix.ing · top · new · best · stats · spec

The small-polaron crossover: Comparison between exact results and vertex correction approximation

1997/10/31 by Massimo Capone, M. Capone S. Ciuchi, C. Grimaldi +2 · 8 citations
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Magnetic and transport properties of perovskites and related materials #Physics of Superconductivity and Magnetism #cond-mat.str-el

paper · pdf · doi:10.1209/epl/i1998-00283-5

published as Europhys. Lett. vol.42, 523-528 (1998) · 6 pages, revtex (europhys.sty,euromacr.tex); 3 postscript figures

openalex publication_date 1998/06/01 · arxiv created 1998/10/01 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30

Abstract

We study the crossover from quasi-free electron to small polaron in the Holstein model for a single electron by means of both exact and self-consistent calculations in one dimension and on an infinite coordination lattice. We show that the crossover occurs when both strong coupling (λ > 1) and multiphonon (α 2 > 1) conditions are fulfilled leading to different relevant coupling constants (λ) in the adiabatic and (α 2 ) antiadiabatic region of the parameters space. We also show that the self-consistent calculations obtained by including the first electron-phonon vertex correction give accurate results in a sizeable region of the phase diagram well separated from the polaronic crossover.

Cited by