SdH oscillations and pressure effect of the Weyl semimetal NbAs

POSTER

Abstract

Via angular Shubnikov-de Hass (SdH) quantum oscillations measurements, we determine the Fermi surface topology of NbAs. The SdH oscillations consist of two frequencies: 20.8 T ($\alpha $-pocket) and 15.6 T ($\beta $-pocket). The analysis shows that the $\beta $-pocket has a Berry phase of $\pi $ and a small effective mass 0.033 m$_{\mathrm{0}}$, indicative of a nontrivial topology; whereas the $\alpha $-pocket has a trivial Berry phase of 0 and a heavier effective mass 0.066 m$_{\mathrm{0}}$. Subtle changes can be seen in the $\rho_{\mathrm{xx}}$(T) profiles with pressure up to 2.31 GPa. The Fermi surfaces undergo an anisotropic evolution under pressure, while the topological features of the two pockets remain unchanged. Specific heat measurements reveal a small Sommerfeld coefficient $\gamma _{\mathrm{0}}=$0.09(1) mJ/(mol\textbullet K$^{\mathrm{2}})$ and a large Debye temperature, $\Theta_{\mathrm{D}}=$450(9) K, confirming a ``hard'' crystalline lattice. The Kadowaki-Woods ratio and a suppressed transport scattering rate are also studied. \textbf{References:} [1] N. J. Ghimire \textit{et al}., JPCM \textbf{27}, 152201 (2015) [2] Y. Luo \textit{et al.}, arXiv: 1506.01751 (2015) [3] Y. Luo \textit{et al.}, arXiv: 1510.08538 (2015)

Authors

  • Yongkang Luo

    • Los Alamos National Laboratory, Los Alamos, NM 87545, USA

  • N. J. Ghimire

    • Argonne National Laboratory, Argonne, Illinois 60439, USA

  • M. Wartenbe

    • Los Alamos National Laboratory, Los Alamos, NM 87545, USA

  • Hongchul Choi

    • Los Alamos National Laboratory, Los Alamos, NM 87545, USA

  • M. Neupane

    • Los Alamos National Laboratory, Los Alamos, NM 87545, USA

  • Ross McDonald

    • Los Alamos National Laboratory, Los Alamos, NM 87545, USA
    • LANL
    • Los Alamos National Laboratory
    • National High MagneticField Laboratory, Los Alamos National Laboratory, Los Alamos, NM, USA.

  • Eric Bauer

    • Los Alamos National Laboratory, Los Alamos, NM 87545, USA
    • Los Alamos National Laboratory

  • Jian-Xin Zhu

    • Theoretical Division and Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
    • Los Alamos National Laboratory, Los Alamos, NM 87545, USA
    • Los Alamos National Laboratory

  • Joe Thompson

    • Los Alamos National Laboratory, Los Alamos, NM 87545, USA
    • Los Alamos National Laboratory

  • Filip Ronning

    • Los Alamos National Laboratory, Los Alamos, NM 87545, USA
    • Los Alamos National Laboratory
    • Los Alamos National Lab