Modulation of Weyl semimetal state in half-Heusler GdPtBi enabled by hydrostatic pressure

Junli Zhang,Peng Li,Enke Liu,Yan Wen,Jie Chen,Chenhui Zhang,Ye Yuan,Lei Jin,Qiang Zhang,Xixiang Zhang,Xiaoming Zhang,Wenhong Wang

doi:10.1088/1367-2630/ac1af6

Abstract

The excitation of Weyl semimetals obeys the relativistic Weyl equation and attracted significant research attention due to its unique electronic state. In this paper, we present an emerging approach for modulating the electron state of half-Heusler GdPtBi by hydrostatic pressure. Through measurements of the temperature-dependent resistivity and magnetoresistance (MR), a phase transition from a Weyl semimetal to a semiconductor state was identified at about 2.0 GPa upon increasing the hydrostatic pressure. Electron transport in semiconductive GdPtBi is found to be well describable by Mott variable-range-hopping. The simulated electronic structures under different hydrostatic pressures further indicate that changes in the electronic states of atoms in the primary unit cell result in a phase transition in GdPtBi. This work presents an effective strategy for modulating the electronic state by tuning the lattice constant.

Highlights

Weyl/Dirac semimetals are a family of quantum materials that recently attracted great attention, with the discovery of topological characters in materials such as TaAs [1, 2], Cd3As2[3, 4], WTe2 [5, 6], ZrTe5 [7, 8], and Na3Bi [9, 10], among others
We identify a phase transition from the Weyl semimetal to the semiconductor state at about 2.0 GPa upon increasing the hydrostatic pressure based on dM
The calculated energy-band and crystalline structures of GdPtBi under different hydrostatic pressures indicate that the change of the electronic states of atoms in the primary unit cell is the origin of this electronic-state transition

Summary

Introduction

Weyl/Dirac semimetals are a family of quantum materials that recently attracted great attention, with the discovery of topological characters in materials such as TaAs [1, 2], Cd3As2. The Weyl points always appear in pairs with distinct chirality and are topologically stable against small perturbations due to topological protection These topological electronic structures enable materials to exhibit broad potential applications and exhibit many novel phenomena, including chiral anomalies, topological surface states, Fermi arcs, and nontrivial Berry phases. Experiments and theories indicated that hydrostatic pressure is an efficient approach for pt tuning the electronic structures of topological materials[22, 23]. The calculated energy-band and crystalline structures of GdPtBi under different hydrostatic pressures indicate that the change of the electronic states of atoms in the primary unit cell is the origin of this electronic-state transition. This work explores pte the underlying physics of the properties of GdPtBi, and presents an efficient strategy for modulating its electronic state. The GGA + U method was applied during our calculations to account for the Coulomb interaction, while the effective U ce values were chosen as 2 eV for the Pt-5d and Gd-4f orbitals

Results and discussion

2.50 GPa ln xx

Summary