Excitonic Phase Transition in Electronic Systems

TL;DR

This paper investigates the theoretical possibility of excitonic phase transitions in electronic systems, concluding that true phase transitions are unlikely in the presence of hybridization, and offers an alternative interpretation for experimental observations.

Contribution

It provides a theoretical analysis showing that excitonic phase transitions do not occur with hybridization and proposes a new interpretation for experimental data.

Findings

No true phase transition occurs with hybridization.

Alternative explanation based on hybridization gap changes.

Clarifies the discrepancy between theory and experiments.

Abstract

Although predicted theoretically excitonic phase transitions have never been observed. Recently it has been claimed that they can occur in some strongly correlated materials. We study the possibility of an excitonic transition in a two-band model and show that a true phase transition never occurs in the presence of hybridization. We suggest an alternative interpretation for these experiments based on the opening or closing of a hybridization gap at a critical pressure.