Title: Modelling Excitons: from vibrational coupling to topology
When: Thursday, January 23, 2025, 12:00
Place: Department of Condensed Matter Physics, Faculty of Sciences, Module 3, Seminar Room (5th Floor)
Speaker: Bartomeu Monserrat, University of Cambridge, UK.
The ground state properties of materials can be readily modelled using density functional theory, which has reached predictive power for many material classes over the past few decades. However, many material properties of interest appear beyond the ground state, with examples including finite temperature and electronic excitations. In turn, these excited state properties play a key role in many technologies, such as light emitting diodes and solar cells. In this talk, I will give an overview of our work in modelling electronic excitations in semiconductors, with a focus on excitons, electron-hole bound pairs that form upon photoexcitation. As a first example, I will describe the microscopic mechanisms driving the interaction of excitons with ionic vibrations, and their impact on exciton optics, dynamics, and transport. As a second example, I will describe exciton topology and exciton quantum geometry, covering both the possible phases and their physical manifestation in properties such as transport.
