Lattice polaron formation: Effects of non-screened electron-phonon interaction

TL;DR

This paper investigates how long-range electron-phonon interactions influence lattice polaron properties using exact diagonalization, revealing differences from the standard short-range Holstein model.

Contribution

It introduces a comprehensive analysis of lattice polarons with long-range interactions, extending beyond the conventional Holstein model.

Findings

Long-range interactions significantly alter polaron effective mass.

Dynamical properties differ notably from short-range models.

The study provides detailed spectral and optical characteristics.

Abstract

We explore the quasiparticle properties of lattice polarons on the basis of a quite general electron-phonon Hamiltonian with a long-range displacement-type of interaction. To treat the dynamical quantum phonons without significant loss of accuracy we adapt an exact Lanczos diagonalization method and compute various static and dynamical quantities, such as the electron-lattice correlation function, the polaron band dispersion, the effective polaron mass, the kinetic energy, the single-particle spectral function, and the optical conductivity, on finite one-dimensional lattices for a wide range of model parameters. We compare the results with those obtained for the standard Holstein model with short-range electron-phonon interaction only.