Observation of magnon-magnon coupling with high cooperativity in Ni80Fe20cross-shaped nanoring array

Kartik Adhikari; Samiran Choudhury; Saswati Barman; Yoshichika Otani; Anjan Barman

doi:10.1088/1361-6528/ac0ddc

Observation of magnon-magnon coupling with high cooperativity in Ni₈₀Fe₂₀cross-shaped nanoring array

Nanotechnology. 2021 Jul 9;32(39). doi: 10.1088/1361-6528/ac0ddc.

Authors

Kartik Adhikari^{1

2}, Samiran Choudhury¹, Saswati Barman³, Yoshichika Otani^{4

5}, Anjan Barman¹

Affiliations

¹ Department of Condensed Matter Physics and Material Sciences, S N Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700106, India.
² Department of Physics, New Alipore College, New Alipore, Kolkata 700053, India.
³ Institute of Engineering and Management, Sector V, Salt Lake, Kolkata 700091, India.
⁴ CEMS-RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
⁵ Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan.

PMID: 34161940
DOI: 10.1088/1361-6528/ac0ddc

Abstract

We report here an experimental observation of dynamic dipolar coupling induced magnon-magnon coupling and spin wave (SW) mode splitting in Ni₈₀Fe₂₀cross-shaped nanoring array. Remarkably, we observe an anticrossing feature with minimum frequency gap of 0.96 GHz and the corresponding high cooperativity value of 2.25. Interestingly, splitting of the highest frequency SW mode occurs due to the anisotropic dipolar interactions between the cross nanorings. Furthermore, using micromagnetic simulations we demonstrate that the coupled SW modes propagate longer as opposed to other modes present in this system. Our work paves the way towards integrated hybrid systems-based quantum magnonics and on-chip coherent information transfer.

Keywords: ferromagnetic nanostructures; magnon–magnon coupling; micromagnetic simulation; spin wave; time-resolved magneto-optical Kerr effect microscope.