Phys.org January 10, 2019
An international team of researchers (Sweden, Portugal) demonstrated how to play and strengthen overtones at the nano level. The researchers have produced spintronic oscillators that strengthen spin wave signals in several steps. When they increased the drive current, the signal showed a sharp jump in frequency: first, from the fundamental frequency of 9 GHz to 14 GHz and then a second jump to 20 GHz. While the wavelength of the fundamental tone is about 500 nanometres, the wavelength of the demonstrated third overtone is as short as 74 nanometres. Future studies on smaller oscillators should be able to generate spin waves down to 15 nanometres with frequencies up to 300 GHz. That is why the potential for extremely high-frequency spintronics and magnonics is enormous. The discovery also makes it possible for researchers to generate very high microwave frequencies with short wavelengths for use in spintronics and magnonics…read more. Open Access TECHNICAL ARTICLE
Illustration shows how the microwave signal jumps from about 10 GHz to 14 GHz and then to 20 GHz when the current is increased. Credit: Johan Åkerman/The University of Gothenburg