TY - JOUR AU - Zhang, L.-C. AU - Onykiienko, Y. A. AU - Buhl, P. M. AU - Tymoshenko, Y. V. AU - Čermák, P. AU - Schneidewind, A. AU - Stewart, J. R. AU - Henschel, A. AU - Schmidt, M. AU - Blügel, S. AU - Inosov, D. S. AU - Mokrousov, Y. TI - Magnonic Weyl states in Cu2OSeO3 JO - Physical review research VL - 2 IS - 1 SN - 2643-1564 CY - College Park, MD PB - APS M1 - FZJ-2020-00418 SP - 013063 PY - 2020 AB - The multiferroic ferrimagnet Cu2OSeO3 with a chiral crystal structure has attracted a lot of recent attention due to the emergence of a magnetic skyrmion order in this material. Here, the topological properties of its magnon excitations are systematically investigated by linear spin-wave theory and inelastic neutron scattering. When considering Heisenberg exchange interactions only, two degenerate Weyl magnon nodes with topological charges ±2 are observed at high-symmetry points. Each Weyl point splits into two as the symmetry of the system is further reduced by including into consideration the nearest-neighbor Dzyaloshinskii-Moriya interaction, crucial for obtaining an accurate fit to the experimental spin-wave spectrum. Also, one additional pair of Weyl points appears near the R point. The predicted topological properties are verified by surface state and Chern number analysis. Additionally, we predict that a measurable thermal Hall conductivity can be associated with the emergence of the Weyl points, the position and number of which can be tuned by modifying the Dzyaloshinskii-Moriya interaction in the system. LB - PUB:(DE-HGF)16 UR - <Go to ISI:>//WOS:000600711800005 DO - DOI:10.1103/PhysRevResearch.2.013063 UR - https://juser.fz-juelich.de/record/872958 ER -