Electrodynamics near the Metal-to-Insulator Transition in V3O5

TL;DR

This study investigates the electrodynamics of V3O5 near its metal-to-insulator transition induced by temperature and pressure, revealing polaronic behavior and electron-lattice interactions as key factors.

Contribution

It provides a detailed infrared spectroscopy analysis showing how polarons influence the MIT in V3O5 under different conditions, highlighting the role of electron-lattice coupling.

Findings

Insulating phase has strongly localized small polarons.

Metallic phase involves incoherent polaron liquid and coexistence of localized and delocalized polarons.

Spectral weight recovery occurs around 1 eV, emphasizing electron-lattice interaction importance.

Abstract

The electrodynamics near the metal-to-insulator transitions (MIT) induced, in V3O5 single crystals, by both temperature (T) and pressure (P) has been studied by infrared spectroscopy. The T- and P-dependence of the optical conductivity may be explained within a polaronic scenario. The insulating phase at ambient T and P corresponds to strongly localized small polarons. Meanwhile the T-induced metallic phase at ambient pressure is related to a liquid of polarons showing incoherent dc transport, in the P-induced metallic phase at room T strongly localized polarons coexist with partially delocalized ones. The electronic spectral weight is almost recovered, in both the T and P induced metallization processes, on an energy scale of 1 eV, thus supporting the key-role of electron-lattice interaction in the V3O5 metal-to-insulator transition.