Quantum oscillations and the Fermi-surface topology of the Weyl semimetal NbP

TL;DR

This study uses quantum oscillation measurements and band-structure calculations to map the Fermi surface of NbP, revealing its topology and potential for observing the chiral anomaly effect in Weyl semimetals.

Contribution

It provides detailed Fermi surface topology of NbP and predicts conditions for realizing the chiral anomaly effect through electron doping.

Findings

Identification of spin-orbit-split electron and hole pockets

Explanation of linear magnetoresistance via quantum-limit scenario

Weyl points located 5 meV above the Fermi energy

Abstract

The Weyl semimetal NbP was found to exhibit topological Fermi arcs and exotic magneto-transport properties. Here, we report on magnetic quantum-oscillation measurements on NbP and construct the 3D Fermi surface with the help of band-structure calculations. We reveal a pair of spin-orbit-split electron pockets at the Fermi energy and a similar pair of hole pockets, all of which are strongly anisotropic. The Fermi surface well explains the linear magnetoresistance observed in high magnetic fields by the quantum-limit scenario. The Weyl points that are located in the $k_z \approx \pi/c$ plane are found to exist 5 meV above the Fermi energy. Therefore, we predict that the chiral anomaly effect can be realized in NbP by electron doping to drive the Fermi energy to the Weyl points.