Sign reversal of the anomalous Hall effect in Co/Pd multilayers

Chun-Yen Chen¹, Yi-Feng Lai¹, Danru Qu³, Ssu-Yen Huang⁴, Yu-Hui Tang¹, Jhen-Yong Hong^5*

¹Department of Physics, National Central University, Taoyuan, Taiwan
²Department of Physics & Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
³Center for Condensed Matter Sciences, National Taiwan University, Taipei, Taiwan
⁴Department of Physics, National Taiwan University, Taipei, Taiwan
⁵Department of Physics, Tamkang University, New Taipei City, Taiwan

* Presenter:Jhen-Yong Hong, email:jyhong@mail.tku.edu.tw

Multilayers of ferromagnet (FM)/heavy metals (HM) with strong spin–orbit coupling exhibit Dzyaloshinskii–Moriya interaction helps to stabilize topological charges such as skyrmions. Here, we fabricate Co/Pd heterostructures and reveal that the sign of the anomalous Hall effect (AHE) in the magnetic multilayers could be changed from being positive to negative with increasing thickness of the Co layer. Upon transition, the formation and stabilization of spin textures in Co/Pd multilayers with topological Hall effect is observed. While the intrinsic AHE can be understood as the consequence of non-zero Berry curvature in momentum space, the regulation of interfacial electronic properties in FM/HM systems could provide a new route to create the Berry curvature change in magnetic multilayers.

Keywords: Dzyaloshinskii-Moriya interaction, Berry curvature, Anomalous Hall effect, Topological Hall effect, Magnetic multilayers