报告题目：Investigation of unusual angular magnetoresistance in nodal line Dirac semimetals
报告时间：2018-09-28 14:00 (星期五)
报告地点：32楼218
报告人：Prof. Mario Novak（克罗地亚Zagreb University 物理系助理教授）

报告摘要：

The Dirac nodal line semimetals have recently attracted a lot of attention due to its unusual Fermi surface, high field magnetic induced break down 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 magneticfield. 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 isin the a-b plane (currentalong 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 themagnetoresistance.

[1] L. M Schoop etal.,  Nature Communications 7, 11696(2016)

[2] S. Prezzini etal., Nature Physics volume 14, 183 (2018)

[3] M. N. Ali etal.,   Science Advances 2, e1601742   (2016) 

报告人简历：

Mario Novak finished his Ph.D. at Department of Physics,  Zagreb where he worked on conducting polymers. Form 2012-2014 he did a postdoc at Osaka University in the group of Yoichi Ando where he had started working on topological insulators and Dirac semimetals. From 2015 he works at Department of Physics in Zagreb as Assistant Professor. In 2017 he stayed at The Institute for Solid State Physics as aVisiting Professor. He published around 20 papers in topics of conducting polymers and topological materials. 

Currently, he isworking 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.