Chiral magnetoresistance in the Weyl semimetal NbP

TL;DR

This paper reports the observation of chiral anomaly-induced negative magnetoresistance in NbP, a Weyl semimetal, achieved by Ga-doping to tune the Fermi energy near the Weyl points, with effects persisting up to room temperature.

Contribution

The study demonstrates the first observation of chiral magnetoresistance in NbP by Fermi level tuning, establishing NbP as a promising platform for Weyltronic applications.

Findings

Observation of negative magnetoresistance under parallel E and B fields

Fermi energy tuned close to Weyl points via Ga-doping

Negative magnetoresistance persists up to room temperature

Abstract

NbP is a recently realized Weyl semimetal (WSM), hosting Weyl points through which conduction and valence bands cross linearly in the bulk and exotic Fermi arcs appear. However, the most intriguing transport phenomenon of a WSM, the chiral anomaly-induced negative magnetoresistance (NMR) in parallel electric and magnetic fields, has yet to be observed in NbP. In intrinsic NbP the Weyl points lie far from the Fermi energy, making chiral magneto-transport elusive. Here, we use Ga-doping to relocate the Fermi energy in NbP sufficiently close to the Weyl points, for which the different Fermi surfaces are verified by resultant quantum oscillations. Consequently, we observe a NMR for parallel electric and magnetic fields, which is considered as a signature of the chiral anomaly in condensed-matter physics. The NMR survives up to room temperature, making NbP a versatile material platform for the development of Weyltronic applications.