Interplay of electronic correlations and lattice instabilities in BaVS3

TL;DR

This paper investigates how electronic correlations, orbital ordering, and lattice instabilities interact in BaVS3, revealing a complex three-step evolution of its optical and electronic properties across the metal-insulator transition.

Contribution

It provides new insights into the interplay of electronic, orbital, and lattice effects in BaVS3, emphasizing the role of electronic correlations in its phase transition.

Findings

Observation of a three-step evolution in optical phonon spectrum

Identification of a precursor fluctuating state at high temperatures

Evidence of orbital ordering and a charge gap at low temperatures

Abstract

The quasi-one-dimensional metallic system BaVS3 with a metal-insulator transition at T_MI=70 K shows large changes of the optical phonon spectrum, a central peak, and an electronic Raman scattering continuum that evolve in a three-step process. Motivated by the observation of a strongly fluctuating precursor state at high temperatures and orbital ordering and a charge gap at low temperatures we suggest a concerted action of the orbital, electronic, and lattice subsystems dominated by electronic correlations.