Optical excitations and disorder in two-dimensional topological insulators

TL;DR

This paper investigates the fundamental electronic properties and disorder effects in two-dimensional topological insulators, focusing on Bismuth compounds, with implications for their use in photovoltaic technologies.

Contribution

It provides a detailed analysis of optical excitations and the impact of structural disorder on 2D topological insulators, emphasizing their potential for technological applications.

Findings

Disorder significantly affects the electronic states of topological insulators.

Bismuth compounds show promise for photovoltaic applications.

Optical excitations reveal unique topological features.

Abstract

Topological phases of matter have garnered significant interest over the past two decades for two main reasons: their identification, via topological invariants, relies on the quantum geometry of the Bloch states, bringing attention to an aspect of electronic band structure overlooked up to their discovery. Secondly, these classes of materials present electronic states with unusual properties, leading to exotic phenomena and making them relevant for potential applications. In this thesis we explore both fundamental and technological aspects of the first discovered topological phase: the topological insulator. To this end, we consider different models of topological insulators with a particular emphasis on Bismuth compounds, evaluating their viability for photovoltaic applications, and separately, the impact of structural disorder on their properties.