Thermopower and Unconventional Nernst Effect in the Predicted Type-II Weyl Semimetal WTe2

Rana KG, Dejene FK, Kumar N, Rajamathi CR, Sklarek K, Felser C, Parkin SSP (2018)

Publication Type: Journal article

Publication year: 2018

Journal

Nano Letters American Chemical Society

Book Volume: 18

Pages Range: 6591-6596

Journal Issue: 10

DOI: 10.1021/acs.nanolett.8b03212

Abstract

WTe2 is one of a series of recently discovered high mobility semimetals, some of whose properties are characteristic of topological Dirac or Weyl metals. One of its most interesting properties is the unsaturated giant magnetoresistance that it exhibits at low temperatures. An important question is the degree to which this property can be ascribed to a conventional semimetallic model in which a highly compensated, high mobility metal exhibits large magnetoresistance. Here, we show that the longitudinal thermopower (Seebeck effect) of semimetallic WTe2 exfoliated flakes exhibits periodic sign changes about zero with increasing magnetic field that indicates distinct electron and hole Landau levels and nearly fully compensated electron and hole carrier densities. However, inconsistent with a conventional semimetallic picture, we find a rapid enhancement of the Nernst effect at low temperatures that is nonlinear in magnetic field, which is consistent with Weyl points in proximity to the Fermi energy. Hence, we demonstrate the role played by the Weyl character of WTe2 in its transport properties.

Involved external institutions

Max-Planck-Institut für Mikrostrukturphysik (MSP) / Max Planck Institute for Microstructure Physics

Germany (DE) Max-Planck-Institut für Chemische Physik fester Stoffe (MPI CPfS) / Max Planck Institute for Chemical Physics of Solids

Germany (DE)

How to cite

APA:

Rana, K.G., Dejene, F.K., Kumar, N., Rajamathi, C.R., Sklarek, K., Felser, C., & Parkin, S.S.P. (2018). Thermopower and Unconventional Nernst Effect in the Predicted Type-II Weyl Semimetal WTe2. Nano Letters, 18(10), 6591-6596. https://doi.org/10.1021/acs.nanolett.8b03212

MLA:

Rana, K. Gaurav, et al. "Thermopower and Unconventional Nernst Effect in the Predicted Type-II Weyl Semimetal WTe2." Nano Letters 18.10 (2018): 6591-6596.

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