Exchange-enhanced ultrastrong magnon-magnon coupling in a compensated ferrimagnet

Liensberger L, Kamra A, Maier-Flaig H, Gepraegs S, Erb A, Goennenwein STB, Gross R, Belzig W, Huebl H, Weiler M (2019)

Publication Type: Journal article

Publication year: 2019

Journal

Physical Review Letters American Physical Society

Book Volume: 123

Article Number: 117204

Journal Issue: 11

DOI: 10.1103/PhysRevLett.123.117204

Abstract

We experimentally study the spin dynamics in a gadolinium iron garnet single crystal using broadband ferromagnetic resonance. Close to the ferrimagnetic compensation temperature, we observe ultrastrong coupling of clockwise and counterclockwise magnon modes. The magnon-magnon coupling strength reaches almost 40% of the mode frequency and can be tuned by varying the direction of the external magnetic field. We theoretically explain the observed mode coupling as arising from the broken rotational symmetry due to a weak magnetocrystalline anisotropy. The effect of this anisotropy is exchange enhanced around the ferrimagnetic compensation point.

Involved external institutions

Bayerische Akademie der Wissenschaften DE Germany (DE) NTNU Trondheim - Norwegian University of Science and Technology NO Norway (NO) Technische Universität Dresden DE Germany (DE) Universität Konstanz DE Germany (DE)

How to cite

APA:

Liensberger, L., Kamra, A., Maier-Flaig, H., Gepraegs, S., Erb, A., Goennenwein, S.T.B.,... Weiler, M. (2019). Exchange-enhanced ultrastrong magnon-magnon coupling in a compensated ferrimagnet. Physical Review Letters, 123(11). https://doi.org/10.1103/PhysRevLett.123.117204

MLA:

Liensberger, Lukas, et al. "Exchange-enhanced ultrastrong magnon-magnon coupling in a compensated ferrimagnet." Physical Review Letters 123.11 (2019).

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