Manual for engineering spin dynamics in nanomagnets

(Nanowerk News) An international team of researchers at the University of California, Riverside, and the Institute of Magnetism in Kyiv, Ukraine, have developed a comprehensive manual for the engineering of spin dynamics in nanomagnets – an important step towards advancing spintronic and quantum information technology.

Despite their small size, nanomagnets – found in most spintronic applications – reveal a rich spin excitation dynamics, or “magnon”, the quantum mechanical unit of spin fluctuations. Due to the nanoscale confinement, nanomagnets can be considered as zero-dimensional systems with discrete magnon spectra, similar to atomic spectra.

“The magnons interact with each other, thereby forming a nonlinear spin dynamic,” said Igor Barsukov, assistant professor of physics and astronomy at UC Riverside and corresponding author on the study that appears in the journal. Physical Review Applied (“Controlling Selection Rules for Magnon Scattering in Nanomagnets by Solving Spatial Symmetry”). “Nonlinear spin dynamics is a big challenge and a big opportunity to improve the performance of spintronic technologies such as spin torque memory, oscillators, and neuromorphic computing.”

Barsukov explains that the magnon interaction follows a set of rules – selection rules. Researchers now postulate this rule in terms of the symmetry of the magnetization configuration and the magnon profile.

The new work continues efforts to tame nanomagnets for next-generation computing technologies. In a previous publication, the team demonstrated experimentally that symmetry could be used to engineer magnon interactions.

“We are aware of the opportunities, but also note that a lot of work needs to be done to understand and formulate the selection rules,” said Barsukov.

According to the researchers, a comprehensive set of rules uncovers the mechanism behind the magnon interaction.

“This can be seen as a guide for spintronics laboratories to debug and design nanomagnet devices,” said Arezoo Etesamirad, the paper’s first author who worked in Barsukov’s lab and recently graduated with a doctorate in physics. “This lays the foundation for developing a suite of experimental tools for tunable magnetic neurons, switchable oscillators, energy-efficient memories, and other quantum and next-generation nanomagnetic applications.”