Doctoral Defense in Physics - Masoumeh Kazemi

Doctoral candidate:
Masoumeh Kazemi

Title of thesis:
The interplay between excitonic and magnetic dynamics in 2D chromium trihalides.

Opponents:
Dr. Mikhail Katsnelson, Professor of theoretical physics at Radboud University, Nijmegen, Netherlands.
Dr. Martin Veis, Professor at the Institute of Physics of Charles University, Prague, Czech Republic.

Advisors:
Dr. Ivan Shelykh, Professor at the Faculty of Physical Sciences, University of Iceland.
Dr. Andrey Kudlis, Researcher at Faculty of Physical Sciences, University of Iceland.

Other members of the doctoral committee:
Dr. Pavel F. Bessarab, Associate Professor at Faculty of Natural Sciences, University of Iceland.
Dr. Christian Schneider, Professor at the Institute of Physics, University of Oldenburg, Germany.

Chair of Ceremony:
Dr. Birgir Hrafnkelsson, Professor and Head of the Faculty of Physical Sciences, University of Iceland.

Abstract:
The synthesis of low-dimensional materials demonstrating excitonic response with magnetic dynamics represents a highly significant and successful achievement in the field of condensed matter physics. This integration holds immense importance for both current and future devices reliant on magnetic memory. The present thesis is devoted to a theoretical analysis of optical excitonic response and magnetic lattice dynamics in two-dimensional materials, in particular monolayers of CrI3 . Combining the results of DFT and Bethe-Salpeter simulations describing excitons with Landau-Lifshits equation describing the dynamics of lattice spin, we construct a microscopic theory of complex magneto-excitonic response and in particular the effect of resonant optical magnetization switching. In addition, our investigation focuses on achieving tunable control over the life time and size of magnetic topological defects such as Néel-type skyrmion. We also demonstrate that the possibility of the formation of magnetic skyrmions, together with large excitonic Zeeman splitting leads to giant scattering asymmetry, which is the necessary prerequisite for the excitonic anomalous Hall effect. This will make it possible to simulate various phenomena associated with coupled exciton-skyrmion dynamics.

About the doctoral candidate:
Masoumeh Kazemi was born and raised in Tehran, Iran. She earned a Bachelor’s and Master’s degree in Physics from Iran. Her doctoral research focused on theoretical analysis of the optical excitonic response and magnetic lattice dynamics in two-dimensional materials, in particular CrI3 monolayers. Masoumeh was actively involved in the educational process at the University of Iceland. She taught the problem solving classes ’Introduction to Quantum mechanics’.