May 04, 2023 |
(Nanowerk News) An international team of researchers at the University of California, Riverside, and the Institute of Magnetism in Kyiv, Ukraine, has developed a comprehensive manual for engineering spin dynamics in nanomagnets – an important step toward advancing spintronic and quantum-information technologies.
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Despite their small size, nanomagnets — found in most spintronic applications — reveal rich dynamics of spin excitations, or “magnons,” the quantum-mechanical units of spin fluctuations. Due to its nanoscale confinement, a nanomagnet can be considered to be a zero-dimensional system with a discrete magnon spectrum, similar to the spectrum of an atom.
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“The magnons interact with each other, thus constituting nonlinear spin dynamics,” said Igor Barsukov, an assistant professor of physics and astronomy at UC Riverside and a corresponding author on the study that appears in the journal Physical Review Applied (“Controlling Selection Rules for Magnon Scattering in Nanomagnets by Spatial Symmetry Breaking”). “Nonlinear spin dynamics is a major challenge and a major opportunity for improving the performance of spintronic technologies such as spin-torque memory, oscillators, and neuromorphic computing.”
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Barsukov explained that the interaction of magnons follows a set of rules – the selection rules. The researchers have now postulated these rules in terms of symmetries of magnetization configurations and magnon profiles.
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The new work continues the efforts to tame nanomagnets for next-generation computation technologies. In a previous publication, the team demonstrated experimentally that symmetries can be used for engineering magnon interactions.
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“We recognized the opportunity, but also noticed that much work needed to be done to understand and formulate the selection rules,” Barsukov said.
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According to the researchers, a comprehensive set of rules reveals the mechanisms behind the magnon interaction.
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“It can be seen as a guide for spintronics labs for debugging and designing nanomagnet devices,” said Arezoo Etesamirad, the first author of the paper who worked in the Barsukov lab and recently graduated with a doctoral degree in physics. “It lays the foundation for developing an experimental toolset for tunable magnetic neurons, switchable oscillators, energy-efficient memory, and quantum-magnonic and other next-generation nanomagnetic applications.”
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