Colossal anomalous Hall effect in the layered antiferromagnetic EuAl2Si2 compound

Abstract

The anomalous Hall effect (AHE), significantly enhanced by the extrinsic mechanism, has attracted attention for its almost unlimited Hall response, which exceeds the upper limit of the Berry curvature mechanism. However, due to the high conductivity in the clean regime and weak skew scattering, it is a great challenge to obtain large anomalous Hall conductivities and large anomalous Hall angles at the same time. Here, we unveil a new magnetic metal system, EuAl₂Si₂, which hosts both colossal anomalous Hall conductivity (σ^A_xy ≥ 10⁴ Ω⁻¹ cm⁻¹) and large anomalous Hall angle (AHA >10%). The scaling relation suggests that the skew scattering mechanism is dominant in the colossal anomalous Hall response and gives rise to a large skew scattering constant. The large effective SOC and large magnetic moment may account for this anomaly. Our results indicate that EuAl₂Si₂ is a good platform to study the extrinsic AHE mechanism.