Brillouin light scattering studies of confined spin waves: linear and nonlinear confinement

doi:10.1016/S0370-1573(00)00116-2

Physics Reports

Volume 348, Issue 6, July 2001, Pages 441-489

https://doi.org/10.1016/S0370-1573(00)00116-2 Get rights and content

Abstract

This review is devoted to both the experimental and theoretical aspects of lateral confinement effects observed for spin waves, with the wavevector in the 10²– $10^{6} cm^{−1}$ range, where the magnetic dipole interaction plays the most important role. The Brillouin light scattering (BLS) technique is a powerful tool for the investigation of these effects. In addition to a high sensitivity, which is characteristic for a standard BLS system, we have extended the method to achieve high lateral spatial (30– $50 μm$ ), as well as temporal (1–2 ns) resolution. This is central for the studies summarized in the review. Two representative experimental situations are reviewed: (1) Spin wave confinement in micron size laterally pattered structures (regular arrays of magnetic dots and wires). We focus on the quantization of spin wave wavevectors due to the lateral boundaries of a dot or a wire, and the influence of the static and dynamic coupling between islands. (2) Spatial, temporal and spatio-temporal confinement of linear and nonlinear spin waves in magnetic ferrite films. The formation, propagation, and collision of envelope solitons and their two-dimensional analogs (spin wave bullets) are analyzed. Both analytical and numerical models for spin waves in quasi-one-dimensional waveguides and in wide films are discussed.

Section snippets

Introduction and theoretical background

The study of spin waves is a powerful method for probing the dynamic properties of magnetic media in general and those of laterally patterned magnetic structures in particular. From spin wave measurements basic information on the magnetic properties, such as magnetic anisotropy contributions, the homogeneity of the internal field, as well as coupling between magnetic elements can be extracted. This information is often hard to obtain by other methods. If the size of an element becomes

Brillouin light scattering on spatially and temporally confined magnetic excitations

In the introduction the concept of the Brillouin light scattering (BLS) technique was presented. In this section we consider the theoretical aspects of BLS from laterally confined spin waves and a novel space- and time-resolved BLS spectrometer recently developed at the University of Kaiserslautern.

Confinement of linear spin waves in laterally patterned films

As it was discussed in the introduction the magnetic dipole interaction mainly determines the dispersion of the spin waves with relatively small wavevectors. Patterning of magnetic films changes the magnetic dipole fields and the spin wave properties accordingly. Investigations of spin waves in patterned films cannot only reveal these changes, but might also be expected to give additional information about the effects, observed in static measurements, like complicated magnetization curves and

Self-confinement of linear and nonlinear propagating spin waves in magnetic films and waveguides

We will now discuss experiments on the linear and nonlinear propagation of spin waves. The experiments described below were performed on two different types of ferrimagnetic garnet films: Yttrium–iron garnet $(Y_{3} Fe_{5} O_{12}, YIG)$ and bismuth substituted iron garnet $(Lu_{0.96} Bi_{2.04} Fe_{5} O_{12}, BIG)$ films. All samples were epitaxially grown on (111)-oriented gadolinium gallium garnet substrates. All BIG films have a thickness of $d=1.5 μm$ whereas the YIG films have a thickness of 5– $7 μm$ . Although the dissipation

Conclusions

In conclusion, this review addressed the theory and experiments on the propagation of linear and nonlinear spin waves in magnetic films, waveguides, and arrays of micrometer size magnetic dots and wires using the BLS technique. We discussed the recently discovered spin wave quantization due to their confinement effects in dots and wires. The stationary and non-stationary nonlinear confinement effects of spin waves were also analyzed. Formation, propagation and collisions of

Acknowledgements

We would like to thank T. Mewes and S. Müller for technical help. Support by the Deutsche Forschungsgemeinschaft and the National Science Foundation (Grant DMR-0072017) for large parts of this work is gratefully acknowledged.

References (85)

S.O. Demokritov et al.
J. Magn. Magn. Mater.
(1999)
Y. Otani et al.
J. Magn. Magn. Mater.
(1999)
O. Fruchart et al.
J. Magn. Magn. Mater.
(1999)
J. Martin et al.
J. Magn. Magn. Mater.
(1999)
G.T. Rado et al.
J. Phys. Chem. Solids
(1959)
R.W. Damon et al.
J. Phys. Chem. Solids
(1961)
H. Suhl
J. Phys. Chem. Solids
(1957)
W. Wernsdorfer et al.
J. Magn. Magn. Mater.
(1995)
S.M. Cherif et al.
J. Magn. Magn. Mater.
(1997)
N. Bardou et al.
J. Magn. Magn. Mater.
(1995)

S. Landis et al.

Appl. Phys. Lett.

(1999)

F. Bloch

Z. Phys.

(1930)

B. Lax et al.

Microwave Ferrites and Ferrimagnetics

(1962)

V.S. Lvov

Wave Turbulence Under Parametric Excitation

(1994)

P.E. Wigen (Ed.)

Nonlinear Phenomena and Chaos in Magnetic Materials

(1994)

M.G. Cottam (Ed.)

Linear and Nonlinear Spin Waves in Magnetic Films and Superlattices

(1994)

C. Herring et al.

Phys. Rev.

(1951)

B.A. Kalinikos et al.

J. Phys. C

(1986)

B. Hillebrands

Phys. Rev. B

(1988)

O. Buettner et al.

Phys. Rev. B

(2000)

A.N. Slavin et al.

IEEE Trans. Magn.

(1994)

A.B. Valyavsky et al.

Sov. Phys. Tech. Phys.

(1989)

G.B. Witham

Linear and Nonlinear Waves

(1974)

A.N. Slavin

Phys. Rev. Lett.

(1996)

M.J. Lighthill

J. Inst. Math. Appl.

(1965)

J.W. Boyle et al.

Phys. Rev. B

(1996)

M. Bauer et al.

Phys. Rev. B

(1997)

B.A. Kalinikos et al.

Sov. Phys. JETP

(1988)

M. Chen et al.

Phys. Rev. B

(1994)

O. Buettner et al.

IEEE Trans. Magn.

(1998)

M. Bauer et al.

Phys. Rev. Lett.

(1998)

L.D. Landau et al.

Electrodynamics of Continuous Media

(1060)

D. Awschalom et al.

Phys. Today

(1995)

M. Hehn et al.

Science

(1996)

C. Chappert et al.

Science

(1998)

M. Grimsditch et al.

Phys. Rev. B

(1998)

B. Hillebrands et al.

J. Appl. Phys.

(1997)

A. Ercole et al.

Phys. Rev. B

(1998)

T. Aign et al.

Phys. Rev. Lett.

(1998)

S.M. Cherif et al.

J. Appl. Phys.

(1999)

P. Kraus et al.

J. Vac. Sci. Technol. B

(1995)

M. New et al.

J. Vac. Sci. Technol. B

(1995)

Cited by (0)

View full text

Physics Reports

Brillouin light scattering studies of confined spin waves: linear and nonlinear confinement

Abstract

Section snippets

Introduction and theoretical background

Brillouin light scattering on spatially and temporally confined magnetic excitations

Confinement of linear spin waves in laterally patterned films

Self-confinement of linear and nonlinear propagating spin waves in magnetic films and waveguides

Conclusions

Acknowledgements

J. Magn. Magn. Mater.

J. Magn. Magn. Mater.

J. Magn. Magn. Mater.

J. Magn. Magn. Mater.

J. Phys. Chem. Solids

J. Phys. Chem. Solids

J. Phys. Chem. Solids

J. Magn. Magn. Mater.

J. Magn. Magn. Mater.

J. Magn. Magn. Mater.

Appl. Phys. Lett.

Z. Phys.

Microwave Ferrites and Ferrimagnetics

Wave Turbulence Under Parametric Excitation

Nonlinear Phenomena and Chaos in Magnetic Materials

Linear and Nonlinear Spin Waves in Magnetic Films and Superlattices

Phys. Rev.

J. Phys. C

Phys. Rev. B

Phys. Rev. B

IEEE Trans. Magn.

Sov. Phys. Tech. Phys.

Linear and Nonlinear Waves

Phys. Rev. Lett.

J. Inst. Math. Appl.

Phys. Rev. B

Phys. Rev. B

Sov. Phys. JETP

Phys. Rev. B

IEEE Trans. Magn.

Phys. Rev. Lett.

Electrodynamics of Continuous Media

Phys. Today

Science

Science

Phys. Rev. B

J. Appl. Phys.

Phys. Rev. B

Phys. Rev. Lett.

J. Appl. Phys.

J. Vac. Sci. Technol. B

J. Vac. Sci. Technol. B