The application of topology to characterize the states of condensed matter is an extremely active field today, illustrated by the tremendous recent work on topological insulators, topological Dirac and Weyl semimetals, and magnetic skyrmion phases. The robustness of topologically nontrivial states is guaranteed by a non-zero topological invariant, which often gives rise to fascinating new physical phenomena like the spin-momentum locking in surface states of topological insulators, the quantum anomalous Hall effect, the chiral anomaly or the topological Hall effect. In addition to being fundamentally interesting, topological protection makes topological states desirable for applications, for example in quantum computing or skyrmion-based spintronic devices.

In this experimental PhD project, we are going to study magnetic materials with nontrivial topology. The applicant will participate in the development of high magnetic field magneto-optical spectrometer and/or magneto-optical microscope capable to resolve magentic domains even in small flakes of Van der Waals magnets. The spectroscopic information will allow us to gain information on the interaction between charge carriers and the magnetic order. We will seak for optical signatures of the semimetallic state: we search for inter Landau-level transitions of linear bands and giant magneto-optical Kerr effect of interband transitions connecting non-trivial bands. Part of the work will be carried out at large scale facilities as a part of on-going international collaboration.