Phonon-assisted insulator-metal transitions in correlated systems driven by doping

TL;DR

This paper explores how electron-phonon interactions affect doping-induced insulator-metal transitions in strongly correlated systems, revealing diverse band structure evolutions and their relation to polaronic phenomena and spectral weight redistribution.

Contribution

It introduces a multiband two-dimensional model incorporating Holstein and SSH electron-lattice couplings to analyze transition mechanisms.

Findings

Different band structure evolutions observed across parameter ranges.

Transition features linked to polaron and bipolaron crossovers.

Spectral weight redistribution influenced by electron-phonon interactions.

Abstract

We consider how electron-phonon interaction influences the insulator-metal transitions driven by doping in the strongly correlated system. Using the polaronic version of the generalized tight-binding method, we investigate a multiband two-dimensional model taking into account both Holstein and Su-Schrieffer-Heeger types of electron-lattice contributions. For adiabatic ratio of the hopping parameter and the phonon field energy, different types of band structure evolution are observed in a wide electron-phonon parameter range. We demonstrate the relationship between transition features and such properties of the system as the polaron and bipolaron crossovers, pseudogap behavior of various origin, orbital selectivity, and the redistribution of the spectral weight due to the electron-phonon interaction.