Faster Spin Waves Make Scientists 1 Step Closer to Magnon Computing

Research is underway to find an alternative to our current electronic computing technology, as electron-based systems have limitations, the journal Science Advances reported.

A new way of transmitting information is emerging from the field of magnonics. Instead of electron exchange, the waves generated in magnetic media could be used for transmission.

However, magnon computing has so far been too slow.

Now, scientists at the University of Vienna have discovered a new method that will boost the potential of magnon computing. When the intensity is increased, the spin waves become shorter and faster, having the potential to make magnonic computing possible.

The study is named ‘Deeply nonlinear excitation of self-normalised short spin waves’.

Magnonics is a new field of research in magnetism, where spin waves play a pivotal role. Local disturbance in the magnetic order of a magnet can propagate as waves through a material. These waves are called spin waves, and the associated quasiparticles are called magnons.

Information is carried by spin waves in the form of angular momentum pulses. Because of this, they can be used as low-power data carriers in smaller and more energy-efficient computers for the future.

The larger the wavelength is, the slower magnon-based data processing units are.

Until now, the wavelength could only be shortened with very complex hybrid structures or a synchrotron.

Scientists at the University of Vienna, in partnership with colleagues from Germany, the Czech Republic, Ukraine, and China, have developed a simpler alternative. They found that if the intensity is increased, spin waves become shorter and faster – a groundbreaking method for magnon computing.

The new magnon computing discovery was explained by co-author of the study and leader of the Vienna NanoMag team, Andrii Chumak, using a metaphor.

Chumak stated: “It is helpful to imagine the method with light. If you change the wavelength of light, its colour changes. But if you change the intensity, only the luminosity changes. In this case, we found a way to change the colour by changing the intensity of the spin waves. This phenomenon allowed us to excite much shorter and much better spin waves.”

The current wavelength found with this system is around 200 nanometres. However, according to numerical simulations, it would be possible to excite even smaller wavelengths.

At this stage, it is very difficult to excite or measure these orders of magnitude.

The discovered system presents a self-locking non-linear shift. This means that the amplitude of excited spin waves is constant. This property is relevant for integrated circuits, allowing different magnetic elements to work together with the same amplitude.

This is also crucial to the construction of more complex systems and to the relations of a magnon computer.

Ultimately, the end goal of a fully functional magnon computer has not been achieved, but this new study brings scientists a step closer to achieving their aim.

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