Adiabatic theory of off-center vibronic polarons: Local dynamics and itinerant features along a linear chain

TL;DR

This paper develops an adiabatic theoretical framework for off-center vibronic polarons, examining their local dynamics and itinerant behavior in linear chains, and explores their impact on the material's electric and optical properties.

Contribution

It introduces a novel adiabatic theory for off-center vibronic polarons, incorporating Coulomb and dispersive interactions to analyze their formation and behavior.

Findings

Polaron off-centering can induce electric dipoles affecting material properties.

Coulomb and dispersive interactions influence polaron pairing and dynamics.

The theory predicts specific local and itinerant features of vibronic polarons.

Abstract

The vibronic mixing by an odd-parity vibrational mode of two opposite-parity nearly-degenerate electronic states at a molecular site may drive the small polaron off-center. An associated electric dipole may occur due to broken inversion symmetry which will exert an effect on the electric, optical and transport properties of the host crystal. We first investigate the polaron field in the non-interacting limit and then include Coulomb and dispersive interactions leading to the formation of polaron pairs.