Ph.D. student: Sergei Vlasov
Name of thesis: Quantum mechanical tunneling between magnetic states
Prof. Dimtrii E. Makarov, University of Texas at Austin, USA
Dr. Oleg A. Tretiakov, Assistant Professor, Tohoku University, Japan
Advisors: Hannes Jónsson, Professor in the Faculty of Physical Sciences at the University of Iceland and Valery M. Uzdin, Professor in the Physics Department of ITMO University in St. Petersburg.
Doctoral committee also included
Viðar Guðmundsson, professor, Faculty of Physical Sciences, University of Iceland
Chair of Ceremony: Ragnar Sigurðsson, Vice-head of Faculty of Physical Sciences.
Magnetic states are used to record and store information. As the dimensions of magnetic elements are reduced to increase storage capacity, the lifetime of prepared magnetic states becomes a growing issue. In this thesis the possibility of quantum mechanical tunneling between magnetic states is studied theoretically and a general expression derived for the temperature at which tunneling becomes the dominant transition mechanism. A method for finding optimal tunneling paths, i.e. so-called instantons, for magnetic systems is developed and used to evaluate the temperature dependent activation energy for thermally assisted tunneling. The methods are applied to several magnetic systems, including molecular magnets and skyrmions in thin magnetic films.
About the Ph.D. student:
Sergei Vlasov was born in 1990 in St. Petersburg, Russia. He graduated in 2013 with an MS degree in applied mathematics from ITMO University in St. Petersburg, Russia. From the fall of 2014, Sergei has been a Ph.D. student in a joint program between the University of Iceland and ITMO University. His topics of interests include quantum mechanics, philosophy and rock climbing.