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Radiation of caustic beams from a collapsing bullet
M P Kostylev1, A A Serga, B Hillebrands
1School of Physics, M013, University of Western Australia, Crawley, WA 6009, Australia.
Physical Review Letters
|April 27, 2011
Summary
Collapsing wave packets in nonlinear media emit dispersive waves. This study examines spin-wave bullets in ferrimagnetic films, revealing caustic beam formation and angle modification due to source motion.
Area of Science:
- Nonlinear optics
- Condensed matter physics
- Wave propagation
Background:
- Wave packet collapse is a phenomenon in nonlinear media.
- Dispersive wave emission can occur during collapse.
- Spin-wave bullets in magnetic films are relevant for information transfer.
Purpose of the Study:
- To theoretically and experimentally investigate wave packet collapse in a (2+1)-dimensional system.
- To analyze the emission of untrapped dispersive waves from collapsing wave packets.
- To study spin-wave bullet propagation in a specific magnetic medium.
Main Methods:
- Theoretical modeling of wave packet dynamics.
- Experimental investigation using in-plane magnetized ferrimagnetic films.
- Analysis of spin-wave bullet propagation and associated wave emission.
Main Results:
- Demonstrated theoretical and experimental evidence of dispersive wave radiation from collapsing wave packets.
- Observed the formation of narrow spin-wave caustic beams due to induced uniaxial anisotropy.
- Showed that the angles of these beams are influenced by the source's motion.
Conclusions:
- Collapsing wave packets in nonlinear media with higher-order dispersion radiate untrapped dispersive waves.
- Induced anisotropy in ferrimagnetic films facilitates the formation of spin-wave caustic beams.
- The dynamics of the source directly impact the angular characteristics of the emitted beams.
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