Special CMP Seminar: Artificial Symmetry Design for Emergent Spin Topologies and Their Excitations

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, ferroelectric meta-surface, and topological spin textures, etc., which do not exist in their ground states. In this presentation, I will share with you one universal strategy for the symmetry design that can be extended into a broad variety of materials. We discover that broken space-inversion symmetry 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) [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 with ultralow energy consumption [3,4,5].

References:

[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);

[5] Aiji Wang, et al., Magnetoelectric exchange spring for spin-wave logic with ultralow energy consumption, under review.

Prof. Jinxing Zhang graduated from department of applied physics at the Hong Kong Polytechnic University in 2009, under the supervision of Profs. Helen Chan and Jiyan Dai. Then he worked as a post-doctoral scholar at the University of California, Berkeley between 2009 and 2012 in Prof. Ramamoorthy Ramesh's group. Prof. Zhang has joined School of Physics and Astronomy at Beijing Normal University as a full professor since 2012. Now he is the associate director of Key Laboratory of Multiscale Spin Physics in Ministry of Education. He is also the director of center on artificial matters and emergent solid states at Beijing Normal University. The ultimate goal of his group is the artificial control of symmetries (time-reversal, space-inversion, gauge) in strongly correlated oxides in order parameters related to spin, polar, cooper pair and their excitations such as magnon, phonon, ferron, fluxon states, etc, and eventually for explorations of emergent quantum phenomena and functionalities that do not exist under their ground symmetries. Recently, he has taken great efforts on exploring the potential applications of those fundamental discoveries on prototype electronic and spintronic devices. He published over 130 peer-reviewed papers including those in Nature Series, Physical Review Letters, etc. as a corresponding author.