2021•ACS NanoRequires access
Berry Phase Engineering in SrRuO3/SrIrO3/SrTiO3 Superlattices Induced by Band Structure Reconstruction
Dongxing Zheng, Yue‐Wen Fang, Senfu Zhang, Peng Li, Yan Wen, Bin Fang, Xin He, Yan Li, Chenhui Zhang, Wen‐Yi Tong, Wenbo Mi, Haili Bai, Husam Niman Alshareef, Zi Qiang Qiu, Xixiang Zhang
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Abstract
The Berry phase, which reveals the intimate geometrical structure underlying quantum mechanics, plays a central role in the anomalous Hall effect. In this work, we observed a sign change of Berry curvatures at the interface between the ferromagnet SrRuO 3 (SRO) layer and the SrIrO 3 (SIO) layer with strong spin–orbit coupling. The negative Berry curvature at the interface, induced by the strongly spin–orbit-coupled Ir 5d bands near the Fermi level, makes the SRO/SIO interface different from the SRO layer that has a positive Berry curvature. These opposite Berry curvatures led to two anomalous Hall effect (AHE) channels with opposite signs at the SRO/SIO interface and in the SRO layer, respectively, resulting in a hump-like feature in the Hall resistivity loop. This observation offers a straightforward explanation of the hump-like feature that is usually associated with the chiral magnetic structure or magnetic skyrmions. Hence, this study provides evidence to oppose the widely accepted claim that magnetic skyrmions induce the hump-like feature.