Orbital anomalous Hall effect in the few-layer Weyl semimetal TaIrTe4

TL;DR

This paper reports the discovery of a linear anomalous Hall effect in nonmagnetic TaIrTe4, driven by current-induced orbital magnetization, revealing new insights into orbital magnetoelectric phenomena in Weyl semimetals.

Contribution

It demonstrates the current-induced orbital magnetization as the origin of the anomalous Hall effects in TaIrTe4, a nonmagnetic Weyl semimetal, and explores their temperature and current dependence.

Findings

Linear anomalous Hall resistance depends on applied current.

Sign reversal of Hall resistance at 100 K indicates nonlinear Hall effect.

Colossal nonreciprocal Hall effect observed with current reversal.

Abstract

We report on the observation of the linear anomalous Hall effect (AHE) in the nonmagnetic Weyl semimetal TaIrTe4. This is achieved by applying a direct current Idc and an alternating current Iac (Iac<<Idc) in TaIrTe4, where the former induces time-reversal symmetry breaking and the latter probes the triggered AHE. The anomalous Hall resistance VacH/Iac shows a linear dependence on Idc and changes sign with the polarity of Idc. In temperature-dependent measurements, VacH/Iac also experiences a sign reversal at 100 K, consistent with the temperature-dependent nonlinear Hall effect (NLHE). Furthermore, in measurements involving only dc transport, the dc Hall voltage exhibits a quadratic relationship with Idc. When the Idc direction is reversed, the Hall resistance changes sign, demonstrating a colossal nonreciprocal Hall effect (NRHE). Our theoretical calculations suggest that the observed linear AHE, NLHE, and NRHE all dominantly originate from the current-induced orbital magnetization compared to the minor spin contribution. This work provides deep insights into the orbital magnetoelectric effect and nonlinear Hall response, promising precise electric control of out-of-plane polarized orbit flow.