Past colloquia and seminars


Investigation of unusual angular magnetoresistance nodal line Dirac semimetals

General public Seminar
12.12.2018 10:00 - 11:00

The Dirac nodal line semimetals have recently attracted a lot of attention due to its unusual Fermi surface, high field magnetic induced breakdown and unusual angular magnetoresistance. [1,2,3] In this seminar we present detail study of magnetoresistance in ZrSiS for various directions 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 between a-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.
[1] L. M Schoop et al., Nature Communications 7, 11696 (2016)
[2] S. Prezzini et al., Nature Physics volume 14, 183 (2018)
[3] M. N. Ali et al., Science Advances 2, e1601742 (2016)

When? 12.12.2018 10:00 - 11:00
Where? PER 08 0.58.5
Chemin du Musée 3
1700 Fribourg
speaker Dr. Mario NOVAK
Department of Physics, Faculty of Science, Zagreb University
Contact Prof. Dr. Ana AKRAP
chemin du Musée 3
1700 Fribourg
026 300 91 08 3