Kolloquiumsvortrag, Dr. Sebastian Wintz, Paul Scherrer Institute Villingen, Switzerland / 11.07.2016
11.07.2016 von 17:15 bis 18:45
Institut Ostufer, Kaiserstraße 2, 24143 Kiel, Raum: Geb. D, "Aquarium"
Titel: "Topological Spin Textures as Spin Wave Emitters"
Abstract:
Today, spin waves are seen as high potential information carrier
for next-generation information and communication devices [1]. This view is based on the substantially reduced energy dissipation and much smaller wavelengths of spin waves compared to traditional charge current
signals. For the implementation
of spin wave technology into applicable devices, however, novel concepts
for the generation, manipulation, and detection of spin waves are yet to be found. With respect to spin wave generation,
it was
typically necessary to either use patterned transducers with sizes on the order
of the desired wavelengths (striplines or point-contacts),
or to
generate those spin waves parametrically by a double-frequency
spatially uniform microwave signal [2]. In this presentation, I will report on a newly discovered concept for the generation of spin
waves, which overcomes the bandwidth limitations
in terms of the minimum wavelength
limit given by the patterning size. This method utilizes the translation of natural topological defects, namely the gyration
of magnetic
vortex cores to generate isotropically
propagating, non-reciprocal spin waves
[3].
Experimentally, such spin-waves
were directly observed by means of time-resolved x-ray microscopy. Furthermore, I
will address directional and one-dimensional spin wave emission in anistropic magnetic
systems.
[1] D. Rosso, “International Technology Roadmap for Semiconductors Explores Next 15
Years of Chip Technology”, www.semiconductors.org, (2014).
[2] A. G. Gurevich and G. A. Melkov,
Magnetization Oscillations and Waves. New York:
CRC,
1996.
[3] S. Wintz et al., submitted (2015).
Today, spin waves are seen as high potential information carrier for next-generation information and communication devices. This is based on the substantially reduced energy dissipation and much smaller wavelengths of spin waves compared to traditional charge current signals. For a device implementation, however, novel concepts for the generation, manipulation, and detection of spin waves are yet to be found. Here, we report on a newly discovered concept for the generation of spin waves, which overcomes typical bandwidth limitations of traditional spin wave excitation methods. Our approach utilizes the gyration of magnetic vortex cores to generate isotropically propagating, non- reciprocal spin waves.