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WTe2 Nano letters 13-09-2018.pdf (1.49 MB)

Thermopower and unconventional Nernst effect in the predicted Type-II Weyl semimetal WTe2

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journal contribution
posted on 2018-11-26, 14:30 authored by K. Gaurav Rana, Fasil DejeneFasil Dejene, Neeraj Kumar, Catherine R. Rajamathi, Kornelia Sklarek, Claudia Felser, Stuart S.P. Parkin
© 2018 American Chemical Society. 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.

Funding

We acknowledge partial support from the ERC Advanced Grant No. 670166 “SORBET” and the ERC Advanced Grant No. 742068 “TOPMAT”.

History

School

  • Science

Department

  • Physics

Published in

Nano Letters

Volume

18

Issue

10

Pages

6591 - 6596

Citation

2018. Thermopower and Unconventional Nernst Effect in the Predicted Type-II Weyl Semimetal WTe2. Nano Letters, 18(10), pp. 6591-6596.

Publisher

ACS Nanoletters

Version

  • AM (Accepted Manuscript)

Publisher statement

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Nano Letters, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/10.1021/acs.nanolett.8b03212.

Publication date

2018-09-21

ISSN

1530-6984

eISSN

1530-6992

Language

  • en

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