报告摘要 |
Over the past decade, we have developed universal strategies (e.g. graded/varying strain, surface/interfacial chemistry, non-equivalent superlattice) to artificially control materials’ symmetry and symmetry break for the emergent phenomena and functionalities, such as magnetoelectric phase transition or topological spin textures, etc. In this presentation, I will share with you one strategy for the symmetry design that can be extended into a broad variety of materials. We discover that space-inversion symmetry can be broken and accompanying “hybrid” Dzyaloshinskii-Moriya interaction can be driven by a graded strain in a correlated oxides, (La,Sr)MnO3. Such a symmetry design in this centrosymmetric ferromagnet results in the stabilization of multiple topological spin textures (skyrmions, spirals, bimerons, etc) at room temperature [1,2]. By further engineering the electronic and spin structures simultaneously, we observe that a chiral magnonic edge state can efficiently propagate through the spiral nanochannels of (La,Sr)MnO3 with a low magnetic damping at room temperature. The selective control of spin-wave propagation prospects the potentials for fabricating nanoscale magnonics devices [3,4] [1] Y. Zhang, et al., Strain-Driven Dzyaloshinskii-Moriya Interaction for Room-Temperature Magnetic Skyrmions, Physical Review Letters 127, 117204 (2021); [2] M. Cai, et al., Stabilization and Observation of Large-Area Ferromagnetic Bimeron Lattice, Physical Review Letters 135, 116703 (2025); [3] C. Liu, et al., Current-controlled propagation of spin waves in antiparallel, coupled domains, Nature Nanotechnology 14, 691-697 (2019); [4] Y. Zhang, et al., Switchable long-distance propagation of chiral magnonic edge states, Nature Materials 24, 69-75 (2025). |
