Dresden 2017 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 19: Transport: Topological Semimetals 1 (jointly with DS, MA, HL, O)

MA 19.4: Vortrag

Dienstag, 21. März 2017, 10:15–10:30, HSZ 201

Angular-dependent magnetoresistance of 3D Dirac materials — •Henry Legg and Achim Rosch — Institute for Theoretical Physics University of Cologne Zülpicher Straße 77 D-50937 Köln Deutschland

The realisation of 3D Dirac and Weyl semi-metals has created a new playground for transport phenomena, such as the possibility to produce the chiral anomaly in a condensed matter setting. Many materials that realise a 3D Dirac dispersion are protected by crystal symmetry and therefore have multiple Dirac cones within their Brillouin zone; examples include Cd₂ As₂, Na₃Bi, and Pb_1−xSn_xSe.

In this work we show that the application of a parallel magnetic and electric field in a direction perpendicular to that connecting a pair of Dirac cones can lead to a large positive magnetoresistance. The magnetic field leaves only an effective one-dimensional dispersion parallel to the field, due to the formation of Landau levels perpendicular to the magnetic field. The result is a large inter-nodal scattering matrix between the two Dirac cones since the Dirac nodes are close in the dimensionally reduced system. Our results are compared to recent experiments on Pb_1−xSn_xSe.