Chiral anomaly induced negative magnetoresistance in topological Weyl semimetal NbAs

TL;DR

This paper investigates the negative magnetoresistance in NbAs caused by the chiral anomaly, revealing differences from NbP and highlighting the role of spin-orbital coupling in topological Weyl semimetals.

Contribution

It demonstrates the intercone transport of Weyl fermions in NbAs under magnetic and electric fields, emphasizing the impact of spin-orbital coupling on magnetoresistance behavior.

Findings

Negative magnetoresistance observed in NbAs due to chiral anomaly

Significant difference in MR behavior between NbAs and NbP

Stronger spin-orbital coupling in NbAs compared to NbP

Abstract

In this paper, we report the intercone transport of Weyl fermions in NbAs with external magnetic field in parallel to electric field, a quantum phenomenon known as the Adler-Bell-Jackiw anomaly. Surprisingly, the resulting negative magnetoresistance (MR) in NbAs shows significant difference from NbP. The observed low-field positive MR dip, which is missing in NbP at low temperatures, indicates that the spin-orbital coupling (SOC) is significantly stronger in NbAs than in the former. The results imply that the contribution of arsenic to SOC in TaAs and NbAs is not negligible.