We present an experimental investigation of radial spin-wave modes in magnetic nano-disks with a vortex ground state. The spin-wave amplitude was measured using a frequency-resolved magneto-optical spectrum analyzer, allowing for high-resolution resonance curves to be recorded. It was found that with increasing excitation amplitude up to about 10 mT, the lowest-order mode behaves strongly non-linearly as the mode frequency redshifts and the resonance peak strongly deforms. This behavior was quantitatively reproduced by micromagnetic simulations. Micromagnetic simulations showed that at higher excitation amplitudes, the spinwaves are transformed into a soliton by self-focusing, and collapse onto the vortex core, dispersing the energy in short-wavelength spinwaves. Additionally, this process can lead to switching of the vortex polarization through the injection of a Bloch point.
References
1.
K.
Guslienko
, X.
Han
, D.
Keavney
, R.
Divan
, and S.
Bader
, “Magnetic vortex core dynamics in cylindrical ferromagnetic dots
,” Phys. Rev. Lett.
96
, 067205
(2006
).2.
S.-B.
Choe
, Y.
Acremann
, A.
Scholl
, A.
Bauer
, A.
Doran
, J.
Stöhr
, and H.
Padmore
, “Vortex core-driven magnetization dynamics
,” Science
304
, 420
–422
(2004
).3.
B.
Van Waeyenberge
, A.
Puzic
, H.
Stoll
, K.
Chou
, T.
Tyliszczak
, R.
Hertel
, M.
Fähnle
, H.
Brückl
, K.
Rott
, G.
Reiss
, I.
Neudecker
, D.
Weiss
, C.
Back
, and G.
Schütz
, “Magnetic vortex core reversal by excitation with short bursts of an alternating field
,” Nature
444
, 461
–464
(2006
).4.
A.
Vansteenkiste
, J.
De Baerdemaeker
, K.
Chou
, H.
Stoll
, M.
Curcic
, T.
Tyliszczak
, G.
Woltersdorf
, C.
Back
, G.
Schütz
, and B.
Van Waeyenberge
, “Influence of domain wall pinning on the dynamics behaviour of magnetic vortex structures: Time-resolved scanning x-ray transmission microscopy in NiFe thin film structures
,” Phys. Rev. B
77
, 144420
(2008
).5.
T.
Kamionka
, M.
Martens
, K.
Chou
, M.
Curcic
, A.
Drews
, G.
Schütz
, T.
Tyliszczak
, H.
Stoll
, B.
Van Waeyenberge
, and G.
Meier
, “Magnetic antivortex-core reversal by circular-rotation spin currents
,” Phys. Rev. Lett.
105
, 137204
(2010
).6.
J.
Park
and P.
Crowell
, “Interactions of spin waves with a magnetic vortex
,” Phys. Rev. Lett.
95
, 167201
(2005
).7.
I.
Neudecker
, K.
Perzlmaier
, F.
Hoffmann
, G.
Woltersdorf
, M.
Buess
, D.
Weiss
, and C. H.
Back
, “Modal spectrum of permalloy disks excited by in-plane magnetic fields
,” Phys. Rev. B
73
, 134426
(2006
).8.
M.
Kammerer
, M.
Weigand
, M.
Curcic
, M.
Noske
, M.
Sproll
, A.
Vansteenkiste
, B.
Van Waeyenberge
, H.
Stoll
, G.
Woltersdorf
, C.
Back
, and G.
Schütz
, “Magnetic vortex core reversal by excitation of spin waves
,” Nat. Commun.
2
, 279
(2011
).9.
L.
Giovannini
, F.
Montoncello
, F.
Nizzoli
, G.
Gubbiotti
, G.
Carlotti
, T.
Okuno
, T.
Shinjo
, and M.
Grimsditch
, “Spin excitations of nanometric cylindrical dots in vortex and saturated magnetic states
,” Phys. Rev. B
70
, 172404
(2004
).10.
M.
Buess
, R.
Höllinger
, K.
Perzlmaier
, U.
Krey
, D.
Pescia
, M.
Scheinfein
, D.
Weiss
, and C.
Back
, “Fourier transform imaging of spin vortex eigenmodes
,” Phys. Rev. Lett.
93
, 077207
(2004
).11.
A.
Awad
, K.
Guslienko
, J.
Sierra
, G.
Kakazei
, V.
Metlushko
, and F.
Aliev
, “Precise probing spin wave mode frequencies in the vortex state of circular magnetic dots
,” Appl. Phys. Lett.
96
, 012503
(2010
).12.
K.
Vogt
, O.
Sukhostavets
, H.
Schultheiss
, B.
Obry
, P.
Pirro
, A. A.
Serga
, T.
Sebastian
, J.
Gonzalez
, K. Y.
Guslienko
, and B.
Hillebrands
, “Optical detection of vortex spin-wave eigenmodes in microstructured ferromagnetic disks
,” Phys. Rev. B
84
, 174401
(2011
).13.
V.
Castel
, J.
Ben Youssef
, F.
Boust
, R.
Weil
, B.
Pigeau
, G.
de Loubens
, V. V.
Naletov
, O.
Klein
, and N.
Vukadinovic
, “Perpendicular ferromagnetic resonance in soft cylindrical elements: Vortex and saturated states
,” Phys. Rev. B
85
, 184419
(2012
).14.
M.-W.
Yoo
, J.
Lee
, and S.-K.
Kim
, “Radial-spin-wave-mode-assisted vortex-core magnetization reversals
,” Appl. Phys. Lett.
100
, 172413
(2012
).15.
O. V.
Pylypovskyi
, D. D.
Sheka
, V. P.
Kravchuk
, F. G.
Mertens
, and Y.
Gaididei
, “Regular and chaotic vortex core reversal by a resonant perpendicular magnetic field
,” Phys. Rev. B
88
, 014432
(2013
).16.
K.-W.
Moon
, B. S.
Chun
, W.
Kim
, Z. Q.
Qiu
, and C.
Hwang
, “Duffing oscillation-induced reversal of magnetic vortex core by a resonant perpendicular magnetic field
,” Sci. Rep.
4
, 6170
(2014
).17.
M.
Helsen
, A.
Gangwar
, A.
Vansteenkiste
, and B.
Van Waeyenberge
, “Magneto-optical spectrum analyzer
,” Rev. Sci. Instrum.
85
, 083902
(2014
).18.
K. S.
Buchanan
, M.
Grimsditch
, F. Y.
Fradin
, S. D.
Bader
, and V.
Novosad
, “Driven dynamic mode splitting of the magnetic vortex translational resonance
,” Phys. Rev. Lett.
99
, 267201
(2007
).19.
A.
Drews
, B.
Krüger
, G.
Selke
, T.
Kamionka
, A.
Vogel
, M.
Martens
, U.
Merkt
, D.
Möller
, and G.
Meier
, “Nonlinear magnetic vortex gyration
,” Phys. Rev. B
85
, 144417
(2012
).20.
O. V.
Sukhostavets
, B.
Pigeau
, S.
Sangiao
, G.
de Loubens
, V. V.
Naletov
, O.
Klein
, K.
Mitsuzuka
, S.
Andrieu
, F.
Montaigne
, and K. Y.
Guslienko
, “Probing the anharmonicity of the potential well for a magnetic vortex core in a nanodot
,” Phys. Rev. Lett.
111
, 247601
(2013
).21.
A.
Vansteenkiste
, J.
Leliaert
, M.
Dvornik
, M.
Helsen
, F.
Garcia-Sanchez
, and B.
Van Waeyenberge
, “The design and verification of mumax3
,” AIP Adv.
4
, 107133
(2014
).22.
M.
Bauer
, O.
Büttner
, S.
Demokritov
, B.
Hillebrands
, V.
Grimalsky
, Y.
Rapoport
, and A.
Slavin
, “Observation of spatiotemporal self-focusing of spin waves in magnetic films
,” Phys. Rev. Lett.
81
, 3769
–3772
(1998
).23.
P.
Drazin
and R.
Johnson
, Solitons: An Introduction
(Cambridge University Press
, 1989
).24.
A. N.
Slavin
, B. A.
Kalinikos
, and N. G.
Kovshikov
, Nonlinear Phenomena and Chaos in Magnetic Materials
(World Scientific
, 1994
).25.
R.
Wang
and X.
Dong
, “Sub-nanosecond switching of vortex cores using a resonant perpendicular magnetic field
,” Appl. Phys. Lett.
100
, 082402
(2012
).26.
A.
Thiaville
, J.
Garcia
, R.
Dittrich
, J.
Miltat
, and T.
Schrefl
, “Micromagnetic study of Block-point-mediated vortex core reversal
,” Phys. Rev. B
67
, 094410
(2003
).© 2015 AIP Publishing LLC.
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