Regensburg 2022 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 25: Topological Semimetals

TT 25.6: Vortrag

Donnerstag, 8. September 2022, 11:00–11:15, H3

High-mobility surface conduction in FeSi at low temperatures — •Carolina Burger, Andreas Bauer, Vivek Kumar, Michael Wagner, Ralf Korntner, and Christian Pfleiderer — Physik-Department, Technische Universität München, D-85748 Garching, Germany

We report a study of the correlated small-band-gap semiconductor FeSi, exhibiting a saturation of resistivity below temperatures of a few Kelvin. The magnetic field dependence of the electrical transport properties provides strong evidence of a high-mobility surface conduction channel, that is insensitive to the additional presence of an impurity band in the bulk. The surface conduction channel shares great similarities with properties reported for topological insulators, but displays a striking lack of sensitivity to the presence of ferromagnetic impurities as studied by means of a series of single crystals with slightly different starting compositions. Here, we report measurements of the specific heat and the magnetic torque in order to shed further light on the nature of the high-mobility surface conduction.

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