A Nanomagnetic-Vortex Oscillator for Applications as a Microwave Source
Small magnetic devices, on the scale of 100 nanometers across, are coming into use for memory devices and are being investigated for new signal processing applications. A nanometer-scale magnetic layer can spontaneously form a vortex state, in which the magnetic-moment direction goes in a circle around a central core (top figure below). Researchers at the Center for Nanoscale Systems at Cornell have found that a direct current flowing perpendicularly to the vortex layer can excite the vortex into a gyrating motion (lower figure). This causes the device to emit a high-quality microwave signal, with a frequency that is much better defined than in previous nanometer-scale magnetic oscillators. This team is now working to develop these devices for a variety of applications in high-frequency signal processing.
Magnetic moment of nanometer scale magnetic layer in a vortex state
Vortex in a gyrating motion that creates a high quality microwave signal
[Lead CNS Investigators: Ralph and Buhrman Groups – Nanomagnetics Thrust, Center for Nanoscale Systems, Cornell University. ]
For additional information see:
- “Magnetic vortex oscillator driven by dc spin-polarized current,” V. S. Pribiag et al., arXiv:cond-mat/0702253
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