# Giant Planar Hall Effect in Topological Metals

## TL;DR

This paper predicts a giant planar Hall effect in topological metals caused by the chiral anomaly, linking it to observed angular narrowing of negative magnetoresistance, thus revealing a new transport phenomenon.

## Contribution

It introduces the concept of the Giant Planar Hall Effect in topological metals and connects it to the chiral anomaly and magnetoresistance behavior.

## Key findings

- Prediction of the Giant Planar Hall Effect in topological metals.
- Relation between GPHE and angular narrowing of negative magnetoresistance.
- Potential explanation for experimental observations in topological materials.

## Abstract

Much excitement has been generated recently by the experimental observation of the chiral anomaly in condensed matter physics. This manifests as strong negative longitudinal magnetoresistance and has so far been clearly observed in Na$_3$Bi, ZrTe$_5$, and GdPtBi. In this work we point out that the chiral anomaly must lead to another effect in topological metals, that has been overlooked so far: Giant Planar Hall Effect (GPHE), which is the appearance of a large transverse voltage when the in plane magnetic field is not aligned with the current. Moreover, we demonstrate that the GPHE is closely related to the angular narrowing of the negative longitudinal magnetoresistance signal, observed experimentally.