Nonlinear Magnon Polaritons

Oscar Lee, Kei Yamamoto, Maki Umeda, Christoph W. Zollitsch, Mehrdad Elyasi, Takashi Kikkawa, Eiji Saitoh, Gerrit E. W. Bauer, and Hidekazu Kurebayashi

Phys. Rev. Lett. 130, 046703 – Published 26 January 2023

Abstract

We experimentally and theoretically demonstrate that nonlinear spin-wave interactions suppress the hybrid magnon-photon quasiparticle or “magnon polariton” in microwave spectra of a yttrium iron garnet film detected by an on-chip split-ring resonator. We observe a strong coupling between the Kittel and microwave cavity modes in terms of an avoided crossing as a function of magnetic fields at low microwave input powers, but a complete closing of the gap at high powers. The experimental results are well explained by a theoretical model including the three-magnon decay of the Kittel magnon into spin waves. The gap closure originates from the saturation of the ferromagnetic resonance above the Suhl instability threshold by a coherent backreaction from the spin waves.

Received 25 January 2022
Revised 19 September 2022
Accepted 7 December 2022

DOI:https://doi.org/10.1103/PhysRevLett.130.046703

Physics Subject Headings (PhySH)

Magnetism Magnetization dynamics Magneto-optics Spintronics

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Oscar Lee ¹, Kei Yamamoto ^2,*, Maki Umeda^2,3, Christoph W. Zollitsch¹, Mehrdad Elyasi⁴, Takashi Kikkawa ⁵, Eiji Saitoh^2,4,5,6, Gerrit E. W. Bauer ^4,7, and Hidekazu Kurebayashi ^1,4,8,†

¹London Centre for Nanotechnology, University College London, London WC1H 0AH, United Kingdom
²Advanced Science Research Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai 319-1195, Japan
³Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
⁴WPI Advanced Institute for Materials Research, Tohoku University, 2-1-1, Katahira, Sendai 980-8577, Japan
⁵Department of Applied Physics, The University of Tokyo, Tokyo 113-8656, Japan
⁶Institute for AI and Beyond, The University of Tokyo, Tokyo 113-8656, Japan
⁷Kavli Institute for Theoretical Sciences, University of the Chinese Academy of Sciences, Beijing 100190, China
⁸Department of Electronic and Electrical Engineering, University College London, London WC1E 7JE, United Kingdom