This title appears in the Scientific Report : 2020 

Magnonic Weyl states in Cu2OSeO3
Zhang, L.-C.
Onykiienko, Y. A. / Buhl, P. M. / Tymoshenko, Y. V. / Čermák, P. / Schneidewind, A. / Stewart, J. R. / Henschel, A. / Schmidt, M. / Blügel, S. / Inosov, D. S. (Corresponding author) / Mokrousov, Y.
Quanten-Theorie der Materialien; PGI-1
Streumethoden; JCNS-2
Quanten-Theorie der Materialien; IAS-1
Physical review research, 2 (2020) 1, S. 013063
College Park, MD APS 2020
Journal Article
Quantum Condensed Matter: Magnetism, Superconductivity
Jülich Centre for Neutron Research (JCNS)
Controlling Configuration-Based Phenomena
Controlling Spin-Based Phenomena
Please use the identifier: in citations.
Please use the identifier: in citations.
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.