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

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. Manipulation of the quantum-metric structure to produce topological phenomena has rarely been studied. Now, flexible control of the quantum-metric structure is demonstrated in a topological chiral antiferromagnet at room temperature.