The anomalous Hall effect (AHE) is a quantum coherent transport phenomenon that conventionally vanishes at elevated temperatures because of thermal dephasing. Therefore, it is puzzling that the AHE can survive in heavy metal (HM)/antiferromagnetic (AFM) insulator (AFMI) heterostructures at high temperatures yet disappears at low temperatures. In this paper, we report that an unconventional high-temperature AHE in HM/AFMI is observed only around the N\'eel temperature of AFM, with large anomalous Hall resistivity up to 40 nΩ cm. This mechanism is attributed to the emergence of a noncollinear AFM spin texture with a non-zero net topological charge. Atomistic spin dynamics simulation shows that such a unique spin texture can be stabilized by the subtle interplay among the collinear AFM exchange coupling, interfacial Dyzaloshinski-Moriya interaction, thermal fluctuation, and bias magnetic field.
@article{arxiv.2301.05486,
title = {Significant Unconventional Anomalous Hall Effect in Heavy Metal/Antiferromagnetic Insulator Heterostructures},
author = {Yuhan Liang and Liang Wu and Minyi Dai and Yujun Zhang and Qinghua Zhang and Jie Wang and Nian Zhang and Wei Xu and Le Zhao and Hetian Chen and Ji Ma and Jialu Wu and Yanwei Cao and Di Yi and Jing Ma and Wanjun Jiang and Jia-Mian Hu and Ce-Wen Nan and Yuan-Hua Lin},
journal= {arXiv preprint arXiv:2301.05486},
year = {2023}
}