Impact of Electron-Hole Correlations on the 1T-TiSe2 Electronic Structure

TL;DR

This paper investigates how electron-hole and electron-phonon interactions influence the electronic structure of 1T-TiSe2, revealing its predominantly semiconducting nature with some metallic features.

Contribution

It provides a theoretical analysis of electron correlations in 1T-TiSe2, clarifying its electronic character and resolving experimental ambiguities.

Findings

1T-TiSe2 is mainly semiconducting with spectral weight crossing the Fermi level.

Electron-hole and electron-phonon correlations significantly affect the electronic structure.

Spectral functions compare semimetallic and semiconducting scenarios.

Abstract

Several experiments have been performed on 1T-TiSe2 in order to identify whether the electronic structure is semimetallic or semiconducting without reaching a consensus. In this paper, we theoretically study the impact of electron-hole and electron-phonon correlations on the bare semimetallic and semiconducting electronic structure. The resulting electron spectral functions provide a direct comparison of both cases and demonstrate that 1T-TiSe2 is of predominant semiconducting character with some spectral weight crossing the Fermi level.