Temperature dependence of the excitonic insulator phase model in 1T-TiSe2

TL;DR

This paper investigates how the excitonic insulator phase in 1T-TiSe2 varies with temperature, using a theoretical model to analyze spectral functions, chemical potential shifts, and resistivity changes in relation to experimental observations.

Contribution

It introduces a temperature-dependent analytical model of the excitonic insulator phase in 1T-TiSe2, linking the order parameter to spectral and electronic properties.

Findings

Spectral function calculations agree with experimental photoemission data.

The model predicts temperature-induced chemical potential shifts.

Resistivity estimates align with observed temperature dependence.

Abstract

Recently, detailed calculations of the excitonic insulator phase model adapted to the case of 1\textit{T}-TiSe$_2$ have been presented. Through the spectral function theoretical photoemission intensity maps can be generated which are in very good agreement with experiment [Phys. Rev. Lett. {\bf 99}, (2007) 146403]. In this model, excitons condensate in a BCS-like manner and give rise to a charge density wave, characterized by an order parameter. Here, we assume an analytical form of the order parameter, allowing to perform temperature dependent calculations. The influence of this order parameter on the electronic spectral function, to be observed in photoemission spectra, is discussed. The resulting chemical potential shift and an estimation of the resistivity are also shown.