近日，日本东北大学的Shunsuke Fukami&TJiahao Han及其研究团队取得一项新进展。经过不懈努力，他们实现拓扑手性反铁磁体中量子度规结构的室温柔性操纵。相关研究成果已于2024年4月22日在国际知名学术期刊《自然—物理学》杂志上。

本文深入研究了拓扑手性反铁磁/重金属Mn₃Sn/Pt异质结构中，电子态的量子结构在室温下与界面自旋织构的相互作用，这种相互作用表现为时间反演奇二阶霍尔效应。同时，研究人员还展示了在适度磁场下对量子度规结构进行灵活调控的能力。这一研究成果为利用量子度规结构构建高效非线性器件提供了可能性。

据悉，量子度规和贝里曲率是描述量子本征态几何的两个基本和不同的因素。尽管贝里曲率在控制各种凝聚态中的作用已经被广泛研究，量子度规，也被预测会引起拓扑现象，却很少被研究，特别是在环境条件下。

附：英文原文

Title: Room-temperature flexible manipulation of the quantum-metric structure in a topological chiral antiferromagnet

Author: Han, Jiahao, Uchimura, Tomohiro, Araki, Yasufumi, Yoon, Ju-Young, Takeuchi, Yutaro, Yamane, Yuta, Kanai, Shun, Ieda, Junichi, Ohno, Hideo, Fukami, Shunsuke

Issue&Volume: 2024-04-22

Abstract: The quantum metric and Berry curvature are two fundamental and distinct factors that describe the geometry of quantum eigenstates. Although the role of the Berry curvature in governing various condensed-matter states has been investigated extensively, the quantum metric, which has also been predicted to induce topological phenomena, has rarely been studied, particularly at ambient conditions. Here we demonstrate the room-temperature manipulation of the quantum-metric structure of electronic states through its interplay with the interfacial spin texture in a topological chiral antiferromagnet/heavy metal Mn3Sn/Pt heterostructure, which is manifested in a time-reversal-odd second-order Hall effect. We also show the flexibility in controlling the quantum-metric structure with moderate magnetic fields. Our results open the possibility of building applicable nonlinear devices by harnessing the quantum-metric structure.

DOI: 10.1038/s41567-024-02476-2

Source: https://www.nature.com/articles/s41567-024-02476-2