Investigation of unusual angular magnetoresistance in ZrSiS – a nodal line Dirac semimetal
Department of Physics, Faculty of Science, Zagreb University
The Dirac nodal line semimetals have recently attracted a lot of attention due to its unusual Fermi surface, high magnetic field induced breakdown and unusual angular magnetoresistance. [1,2,3] In this seminar we present detail study of magnetoresistance in ZrSiS for various directions of current and magnetic field. ZrSiS has the tetragonal structure with several Fermi pockets which host closed and open orbits in a magnetic field. The anisotropy of the resistance betweena-b plane and c-direction of a factor of 40 at a low temperature. The transverse angular magnetoresistance has a peak-like structure when the magnetic field is in the a-b plane (current along the c-direction). Moreover, by rotating the magnetic field in the a-b plane, we revealed large in-plane anisotropy. When the current flows in the a-b plane, the transverse angular magnetoresistance reveals interesting butterfly-shaped pattern. To explain the interesting observation of angular magnetoresistance, we used ARPES and numerical simulations that managed to give us detail insight in which Fermi pocket is responsible for the unusual shape of the magnetoresistance.
 L. M Schoop et al., Nature Communications 7, 11696 (2016)
 S. Prezzini et al., Nature Physics volume 14, 183 (2018)
 M. N. Ali et al., Science Advances 2, e1601742 (2016)
Prof. Mario Novak finished his PdH at Department of Physics, Zagreb where he worked on conducting polymers. From 2012 to 2014 he did a postdoc at Osaka University in the group of Yoichi Ando where he has started working on topological insulators and Dirac semimetals. From 2015 he worked at Department of Physics in Zagreb as Assistant professor. In 2017 he stayed at the Institute for Solid State Physics as a Visiting Professor. He published around 20 papers in topics of conducting polymers and topological materials.
Currently, he is working on setting up a new synthesis lab in Zagreb. In general, he is working on material synthesis (single crystals of high quality) and investigation of low-temperature transport properties of novel Dirac and Weyl semimetals.