Demonstration of the third-order nonlinear Hall effect in topological Dirac semimetal NiTe$_2$

TL;DR

This paper reports the experimental observation of a third-order nonlinear Hall effect in the topological Dirac semimetal NiTe$_2$, confirming theoretical predictions and highlighting its independence from external magnetic fields.

Contribution

First experimental demonstration of the third-order nonlinear Hall effect in a Dirac semimetal, expanding understanding of nonlinear transport phenomena in topological materials.

Findings

Third harmonic Hall response observed in NiTe$_2$

Second-order nonlinear Hall effect is negligible in NiTe$_2$

Third harmonic signal is independent of external magnetic field

Abstract

We experimentally investigate third-order nonlinear Hall effect for three-dimensional NiTe$_2$ single crystal samples. NiTe$_2$ is the recently discovered type-II Dirac semimetal, so both the inversion and the time-reversal symmetries are conserved in the bulk. As a result, the well known second-order nonlinear Hall effect does not expected for this material, which we confirm as negligibly small second-harmonic transverse Hall voltage response to the longitudinal ac electric current. As the main experimental result, we demonstrate the unsaturated third-harmonic Hall response in NiTe$_2$, which well corresponds to the theoretically predicted third-order nonlinear Hall effect in Dirac semimetals. We also demonstrate, that the third harmonic signal does not depend on the external magnetic field, in contrast to the field-depended first-order and second-order Hall effects.