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Anomalous electronic structure and magnetoresistance in TaAs2.

ABSTRACT: The change in resistance of a material in a magnetic field reflects its electronic state. In metals with weakly- or non-interacting electrons, the resistance typically increases upon the application of a magnetic field. In contrast, negative magnetoresistance may appear under some circumstances, e.g., in metals with anisotropic Fermi surfaces or with spin-disorder scattering and semimetals with Dirac or Weyl electronic structures. Here we show that the non-magnetic semimetal TaAs2 possesses a very large negative magnetoresistance, with an unknown scattering mechanism. Density functional calculations find that TaAs2 is a new topological semimetal [?2 invariant (0;111)] without Dirac dispersion, demonstrating that a negative magnetoresistance in non-magnetic semimetals cannot be attributed uniquely to the Adler-Bell-Jackiw chiral anomaly of bulk Dirac/Weyl fermions.

SUBMITTER: Luo Y

PROVIDER: S-EPMC4895157 | biostudies-other | 2016

REPOSITORIES: biostudies-other

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Anomalous electronic structure and magnetoresistance in TaAs2.

Luo Yongkang Y McDonald R D RD Rosa P F S PF Scott B B Wakeham N N Ghimire N J NJ Bauer E D ED Thompson J D JD Ronning F F

Scientific reports 20160607

The change in resistance of a material in a magnetic field reflects its electronic state. In metals with weakly- or non-interacting electrons, the resistance typically increases upon the application of a magnetic field. In contrast, negative magnetoresistance may appear under some circumstances, e.g., in metals with anisotropic Fermi surfaces or with spin-disorder scattering and semimetals with Dirac or Weyl electronic structures. Here we show that the non-magnetic semimetal TaAs2 possesses a ve ...[more]

PMID: 27271852

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