Doctoral defence in Physics - Valerii Kozin

Live stream: https://livestream.com/hi/doktorsvornvaleriikozin

Ph.D. student: Valerii Kozin

Dissertation title: Topology and symmetry-breaking in the strong light-matter coupling regime

Opponents:
Dr. ‪Iacopo Carusotto, Senior Researcher at the INO-CNR BEC Center in Trento, Italy
Dr. Leonid Golub, Head of the Sector of Theory of Quantum Coherent Phenomena in Solids, The Ioffe Institute, St. Petersburg, Russia

Advisor: Dr. Ivan Shelykh, Professor at the Faculty of Physical Sciences at the University of Iceland

Doctoral committee: 
Dr. Ivan V. Iorsh, Associate Professor at the Department of Nanophotonics and Metamaterials, ITMO University, St. Petersburg, Russia
Dr. Hafliði Gíslason, Professor at the Faculty of Physical Sciences, University of Iceland
Dr. Viðar Guðmundsson, Professor at the Faculty of Physical Sciences, University of Iceland

Chair of Ceremony: Dr. Einar Örn Sveinbjörnsson, Professor and Head of the Faculty of Physical Sciences, University of Iceland

Abstract:
The physics of light-matter interactions is a rapidly developing research area at the junction between condensed matter physics and quantum optics. Depending on the strength of the light-matter interaction the systems behave very differently. In the current thesis, we mainly (but not exclusively), focus on the regime of (ultra)strong light-matter interaction. Typically, the strong coupling regime implies the employment of various low-dimensional semiconductor structures embedded into a microcavity, or irradiation by a strong laser field, or considering cold atoms, trapped in the vicinity of a waveguide.

In the current thesis, we investigate various quantum systems and phenomena in the (ultra)strong coupling regime, including:

1) topological insulator based on a two-dimensional array of dressed quantum rings;

2) the new type of a polariton $\mathbb{Z}$ topological insulator;

3) Bose-Einstein condensate in a tilted polariton ring;

4) chiral waveguide quantum optomechanics;

5) the new type of a Hall effect for composite particles (excitons), that we refer to as the anomalous exciton Hall effect;

6) transition metal dichalcogenide polaritons in the presence of free carriers; and other related phenomena.

About the doctoral candidate:

Valerii Kozin was born in Almaty (Kazakhstan) in 1992. At the age of 14, he moved to St. Petersburg (Russia), where he entered the Lyceum "Physical-Technical High School" (PTHS). In 2010 Valerii finished high school and entered Peter the Great St. Petersburg Polytechnic University (SPbPU) and graduated in 2015 with a BSc degree in Physics. In 2015 Valerii entered the Academic University (SPbAU RAS) where he got an MSc degree in Physics. In 2017 Valerii got married and started his PhD studies at the University of Iceland (jointly with the ITMO University). During his studies, Valerii published 15 papers in high-ranking journals, including 3 in Physical Review Letters. Valerii was actively involved in the educational process at the University of Iceland, he taught problem classes “Introduction to quantum mechanics” and “Nuclei and Particles”. After the defense, Valerii plans to continue his research in the field of theoretical condensed matter physics.