Megahertz dynamics in skyrmion systems probed with muon-spin relaxation

Hicken, T.J.; Wilson, M.N.; Franke, K.J.A.; Huddart, B.M.; Hawkhead, Z.; Gomilšek, M.; Clark, S.J.; Pratt, F.L.; Štefančič, A.; Hall, A.E.; Ciomaga Hatnean, M.; Balakrishnan, G.; Lancaster, T.

Abstract

We present longitudinal-field muon-spin relaxation (LF μ SR ) measurements on two systems that stabilize a skyrmion lattice (SkL): Cu 2 OSeO 3 , and Co x Zn y Mn 20 − x − y for ( x , y ) = ( 10 , 10 ) , (8, 9), and (8, 8). We find that the SkL phase of Cu 2 OSeO 3 exhibits emergent dynamic behavior at megahertz frequencies, likely due to collective excitations, allowing the SkL to be identified from the μ SR response. From measurements following different cooling protocols and calculations of the muon stopping site, we suggest that the metastable SkL is not the majority phase throughout the bulk of this material at the fields and temperatures where it is often observed. The dynamics of bulk Co 8 Zn 9 Mn 3 are well described by ≃ 2 GHz excitations that reduce in frequency near the critical temperature, while in Co 8 Zn 8 Mn 4 we observe similar behavior over a wide range of temperatures, implying that dynamics of this kind persist beyond the SkL phase.

Citation

Hicken, T., Wilson, M., Franke, K., Huddart, B., Hawkhead, Z., Gomilšek, M., Clark, S., Pratt, F., Štefančič, A., Hall, A., Ciomaga Hatnean, M., Balakrishnan, G., & Lancaster, T. (2021). Megahertz dynamics in skyrmion systems probed with muon-spin relaxation. Physical Review B, 103(2), https://doi.org/10.1103/physrevb.103.024428

• Journal Article Type: Article
• Acceptance Date: Dec 14, 2020
• Online Publication Date: Jan 19, 2021
• Publication Date: 2021
• Deposit Date: Feb 4, 2021
• Publicly Available Date: Sep 23, 2021
• Journal: Physical review B: Condensed matter and materials physics
• Print ISSN: 2469-9950
• Electronic ISSN: 2469-9969
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 103
• Issue: 2
• DOI: https://doi.org/10.1103/physrevb.103.024428
• Public URL: https://durham-repository.worktribe.com/output/1253099
• Related Public URLs: https://arxiv.org/abs/2011.10330