Physicists Generate New Nanoscale Spin Waves
Strong alternating magnetic fields can be utilized to generate a new kind of spin wave that was previously just theoretically anticipated. A team of physicists from Martin Luther College Halle-Wittenberg (MLU) achieved this for the first time. They report on their work in Nature Communications and offer the first microscopic pictures of these spin waves.
The basic concept of spintronics is to use a unique property of electrons– spin– for various electronic applications like data and information technology. The spin is the intrinsic angular momentum of electrons that creates a magnetic moment.
Coupling these magnetic moments produces the magnetism that could ultimately be utilized in information processing. When these paired magnetic moments are locally excited by a magnetic field pulse, this dynamic can spread like waves throughout the product. These are called spin waves or magnons.
A special kind of those waves is at the heart of the work of the physicists from Halle. Usually, the non-linear excitation of magnons produces integers of the output regularity– 1,000 megahertz becomes 2,000 or 3,000, for example.
“So far, it was just theoretically predicted that non-linear processes can produce spin waves at greater half-integer multiples of the excitation frequency,” describes Professor Georg Woltersdorf from the School of Physics at MLU. The team has currently been able to show experimentally which conditions are needed to generate these waves and to control their phase. Stage is the state of the oscillation of a wave at a particular point and time. “We are the 1st to confirm these excitations in experiments and have also been able to map them,” states Woltersdorf.
According to the physicist, the waves could be produced in two stable phase states, which means this discovery could potentially be utilized in data processing applications since computers, for example, additionally use a binary system.
More information:
Rouven Dreyer et al, Imaging and phase-locking of non-linear spin waves, Nature Communications (2022). DOI: 10.1038/s41467-022-32224-0
Read the original article on PHYS.
