Publication Date:
2016-08-11
Description:
Author(s): S. Wiedmann, A. Jost, B. Fauqué, J. van Dijk, M. J. Meijer, T. Khouri, S. Pezzini, S. Grauer, S. Schreyeck, C. Brüne, H. Buhmann, L. W. Molenkamp, and N. E. Hussey Magnetoresistance studies are one of the simplest yet powerful tools to investigate the electronic properties of solids. The authors here report on high-field angle-dependent magnetotransport measurements on epitaxial thin films of Bi 2 Se 3 , a three-dimensional topological insulator. At low temperature, they observe quantum oscillations that demonstrate the simultaneous presence of bulk and surface carriers. Their key observation is a strong anisotropy in the magnetoresistance in Bi 2 Se 3 that depends on the orientation of the applied current (electric field) with respect to the applied magnetic field. When the magnetic field is applied parallel to the electric field, they find a strong negative longitudinal magnetoresistance (NLMR) that, quite strikingly, persists even up to room temperature. With this finding, the authors demonstrate that the observation of a NLMR is not unique to topological semimetals, such as Weyl semimetals, and therefore cannot by itself be taken as a diagnostic tool and as conclusive evidence for the existence of Weyl fermions. These results could pave the way towards a general understanding of the emergence of the axial anomaly that is suggested to be a universal phenomenon for generic three-dimensional metals in the presence of parallel electric and magnetic fields. [Phys. Rev. B 94, 081302(R)] Published Wed Aug 10, 2016
Keywords:
Semiconductors II: surfaces, interfaces, microstructures, and related topics
Print ISSN:
1098-0121
Electronic ISSN:
1095-3795
Topics:
Physics
Permalink
