Generic chiral anomaly and planar Hall effect in a non-Weyl system

Abstract The condensed-matter version of the chiral anomaly describes how electrons are pumped from a Weyl node with negative chirality to a Weyl node with positive chirality using parallel electric and magnetic fields. Key experimental signatures are a negative longitudinal magnetoresistance and the planar Hall effect, both of which have been experimentally observed. Here, we show that the chiral anomaly explains key features of magnetotransport in the nodal-line semimetal zirconium pentatelluride despite the absence of Weyl points. The anomaly physics applies generically to materials in the quantum limit, when electron transport becomes quasi-one-dimensional, provided that Fermi velocities remain sufficiently large. This explains not only the negative longitudinal magnetoresistance but also the planar Hall effect with a gigantic Hall angle and a highly unusual magnetic-field-angle dependence in zirconium pentatelluride.