# Non-linear Hall effect in three-dimensional Weyl and Dirac semimetals

## TL;DR

This paper reports the experimental observation of a non-linear Hall effect in three-dimensional Weyl and Dirac semimetals, highlighting its magnetic field dependence and distinguishing it from thermoelectric effects.

## Contribution

First experimental demonstration of non-linear Hall effect in 3D Weyl and Dirac semimetals with analysis of magnetic field dependence.

## Key findings

- Finite second-harmonic Hall voltage observed
- Hall voltage depends quadratically on current
- Magnetic field dependence distinguishes effect from thermoelectric response

## Abstract

We experimentally investigate a non-linear Hall effect for three-dimensional WTe$_2$ and Cd$_3$As$_2$ single crystals, representing Weyl and Dirac semimetals, respectively. We observe finite second-harmonic Hall voltage, which depends quadratically on the longitudinal current in zero magnetic field. Despite this observation well corresponds to the theoretical predictions, only magnetic field dependence allows to distinguish the non-linear Hall effect from a thermoelectric response. We demonstrate that second-harmonic Hall voltage shows odd-type dependence on the direction of the magnetic field, which is a strong argument in favor of current-magnetization effects. In contrast, one order of magnitude higher thermopower signal is independent of the magnetic field direction.