Vienna scientists enhance magnonic computing with spin wave insights

Vienna scientists enhance magnonic computing with spin wave insights
by Robert Schreiber
Berlin, Germany (SPX) Aug 17, 2023

Global researchers have long been delving into alternatives to traditional electronic computing systems due to inherent limitations associated with electron-based technologies. Magnonics, a burgeoning field in magnetism, is proving to be a promising contender. Unlike conventional methods relying on the exchange of electrons, magnonics harnesses waves generated within magnetic media for data transmission. However, the speed at which magnonics-based computing has operated has previously been less than ideal. That might be set to change.

A significant breakthrough has come from the researchers at the University of Vienna. They have found that by increasing the intensity of the waves, spin waves become shorter and consequently faster. This discovery can pave the way for faster and more efficient magnon computing. Their findings were recently featured in the esteemed journal, Science Advances.

To understand the concept of magnonics, one must first familiarize themselves with spin waves. These waves arise from a localized disturbance in a magnet's magnetic order, which then travels through the material. The associated quasiparticles, termed magnons, transport information using angular momentum pulses. Given their unique properties, they hold the potential to revolutionize the future of computing by being employed as energy-efficient, low-power data carriers in compact computer systems.

However, the field of magnonics isn't without its challenges. A pivotal factor determining the efficiency of magnon-based computing systems is the wavelength of spin waves. A larger wavelength is synonymous with slower processing speeds. Earlier attempts to shorten the wavelength necessitated complex hybrid structures or the use of a synchrotron. But the research team from the University of Vienna, collaborating with experts from Germany, the Czech Republic, Ukraine, and China, has unveiled a more streamlined solution. Qi Wang, the first author of the study, made the enlightening observation: by amplifying the intensity, the spin waves are shortened and thus quickened.

Describing the groundbreaking discovery, Andrii Chumak, co-author and leader of the Vienna NanoMag team, drew an illuminating parallel: "Imagine the workings of light. Adjusting the wavelength alters its color. Yet, modifying the intensity only affects the luminosity. In our research, we essentially changed the 'color' by adjusting the intensity of the spin waves, enabling the excitation of much shorter and superior spin waves."

This discovery has shown spin waves with wavelengths as short as 200 nanometers. Although numerical models suggest even smaller wavelengths are achievable, the current technology finds it challenging to either excite or measure these extremely short wavelengths.

For the grand vision of integrated magnetic circuits, the amplitude of the spin waves is of paramount importance. The newly identified system showcases a self-locking nonlinear shift. In layman's terms, the amplitude of the excited spin waves remains steady. This consistency is pivotal for the interoperability of different magnetic elements within integrated circuits, fostering the potential to build more intricate systems. The dream of a fully-operational magnon computer still remains on the horizon, but with these new insights, the scientific community is significantly closer to transforming this vision into reality.

Research Report:Deeply nonlinear excitation of self-normalized short spin waves