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Tuning of anomalous magnetotransport properties in half-Heusler topological semimetal GdPtBi

Orest Pavlosiuk, Piotr Wiśniewski, Romain Grasset, Marcin Konczykowski, Andrzej Ptok, Dariusz Kaczorowski

Abstract

Half-Heusler compounds from the $RE$PtBi family exemplify Weyl semimetals in which external magnetic field induce Weyl nodes. These materials exceptionally host topologically non-trivial states near the Fermi level and their manifestation can be clearly seen in the magnetotransport properties. In this study, we tune the Fermi level of the archetypal half-Heusler Weyl semimetal GdPtBi through high-energy electron irradiation, moving it away from the Weyl nodes to investigate the resilience of the contribution of topologically non-trivial states to magnetotransport properties. Remarkably, we observe that the negative longitudinal magnetoresistance, which is a definitive indicator of the chiral magnetic anomaly occurring in topological semimetals, persists even when the Fermi level is shifted by 100\,meV from its original position in the pristine sample. Additionally, the anomalous Hall effect shows complex variations as the Fermi level is altered, attributed to the energy-dependent nature of the Berry curvature, which arises from avoided band crossing. Our findings show the robust influence of Weyl nodes on the magneto-transport properties of GdPtBi, irrespective of the Fermi level position, a behaviour likely applicable to many half-Heusler Weyl semimetals.

Tuning of anomalous magnetotransport properties in half-Heusler topological semimetal GdPtBi

Abstract

Half-Heusler compounds from the PtBi family exemplify Weyl semimetals in which external magnetic field induce Weyl nodes. These materials exceptionally host topologically non-trivial states near the Fermi level and their manifestation can be clearly seen in the magnetotransport properties. In this study, we tune the Fermi level of the archetypal half-Heusler Weyl semimetal GdPtBi through high-energy electron irradiation, moving it away from the Weyl nodes to investigate the resilience of the contribution of topologically non-trivial states to magnetotransport properties. Remarkably, we observe that the negative longitudinal magnetoresistance, which is a definitive indicator of the chiral magnetic anomaly occurring in topological semimetals, persists even when the Fermi level is shifted by 100\,meV from its original position in the pristine sample. Additionally, the anomalous Hall effect shows complex variations as the Fermi level is altered, attributed to the energy-dependent nature of the Berry curvature, which arises from avoided band crossing. Our findings show the robust influence of Weyl nodes on the magneto-transport properties of GdPtBi, irrespective of the Fermi level position, a behaviour likely applicable to many half-Heusler Weyl semimetals.
Paper Structure (13 sections, 11 figures)

This paper contains 13 sections, 11 figures.

Table of Contents

  1. Introduction
  2. Results and discussion
  3. Electrical resistivity
  4. Hall effect
  5. Magnetoresistance
  6. Anomalous Hall effect
  7. Electronic band structure calculations
  8. Conclusions
  9. Methods
  10. Single crystals growth and characterization
  11. Electronic transport measurements
  12. Electron irradiation
  13. Ab initio calculation

Figures (11)

  • Figure 1: Temperature dependence of the electrical resistivity (a) and normalised electrical resistivity to the value of $\rho$ recorded at $T=300$ K (b) of pristine and irradiated GdPtBi samples, measured with an electrical current (j) applied along [001] crystallographic direction and in zero magnetic field.
  • Figure 2: Magnetic field dependence of Hall electrical resistivity at $T=10$ K (a) and $T=50$ K (b). Carrier concentration (c) and carrier mobility (d) as a function of irradiation dose at $T=50$ K.
  • Figure 3: Transverse magnetoresistance of pristine and electron irradiated samples at $T=10$ K (a) and $T=50$ K (e). Longitudinal magnetoresistance of pristine and electron irradiated samples at $T=10$ K (b) and $T=50$ K (f). Transverse (c, g) and longitudinal (d, h) magnetoresistance as a function of irradiation dose recorded in $B = 14$ T and at $T=10$ K (c, d) and at $T=50$ K (g, h). Violet lines in (c, d, g, h) are guides for the eye.
  • Figure 4: Transverse (a) and longitudinal (b) magnetoresistance of pristine and electron irradiated samples as a function of carrier mobility (a) and carrier concentration (b) at $T=50$ K and in $B=14$ T. Pink lines are guides for the eye.
  • Figure 5: (a) Anomalous Hall conductivity as a function of magnetic field at $T=10$ K for pristine and irradiated sample. (b) Maximum values of anomalous Hall conductivity (right axis) and magnetic field values (left axis) at which these maxima were recorded as a function of irradiation dose at $T=10$ K.
  • ...and 6 more figures