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K. G. Fripp

Publications and source records attributed to K. G. Fripp.

3 recordsLinked to original sources

Magnonic Full Adder Based on 2D Chiral Magnonic Resonators

We use micromagnetic simulations to demonstrate how machine learning can be applied to arrays of chiral magnonic resonators to build a magnonic full adder. The chiral magnonic resonators have form of nano-sized permalloy disks that nonlinearly scatter spin waves propagating in a YIG waveguide. The spin waves are injected from multiple outputs, and the dynamic stray magnetic field of the scattered spin waves is sampled in multiple locations to form several physical output signals. These signals are weighted and combined, either linearly or nonlinearly, to satisfy the logic output of a full adder. The process is known as training and forms the device's output layer. The full adder's performance is evaluated in terms of robustness to input and output noise for a given number of physical output signals and the form of the output layer. When the output layer is linear, as few as three physical signals per logical output are sufficient. When a multilayer perceptron neural network forms the output layer, the number of required output signals is reduced to one, and a nearly perfect classification accuracy is achieved when appropriate preprocessing and augmentation strategies are used.

physics.app-ph

Nanoscale Magnonic Neurons

We use micromagnetic simulations to demonstrate neuron functionality of two-dimensional (2D) chiral magnonic resonators. Our design exploits nonlinear resonant scattering of spin waves propagating in a YIG medium from an edge mode of a permalloy nano-element. The reduced frequency and volume of the edge mode facilitate matching it to the YIG modes and give rise to their wide-angle scattering. As the amplitudes of the incident spin waves increase, the edge mode exhibits a positive nonlinear frequency shift. This shift leads to a complex frequency-dependent nonlinear variation of the amplitude and phase of spin waves scattered in different directions. We show that the scattered waves are strong enough to activate secondary neurons. This provides the connectivity required for combining our proposed neurons into 2D magnonic neural networks.

physics.app-ph

Roadmap on Spin-Wave Computing

Magnonics is a field of science that addresses the physical properties of spin waves and utilizes them for data processing. Scalability down to atomic dimensions, operations in the GHz-to-THz frequency range, utilization of nonlinear and nonreciprocal phenomena, and compatibility with CMOS are just a few of many advantages offered by magnons. Although magnonics is still primarily positioned in the academic domain, the scientific and technological challenges of the field are being extensively investigated, and many proof-of-concept prototypes have already been realized in laboratories. This roadmap is a product of the collective work of many authors that covers versatile spin-wave computing approaches, conceptual building blocks, and underlying physical phenomena. In particular, the roadmap discusses the computation operations with Boolean digital data, unconventional approaches like neuromorphic computing, and the progress towards magnon-based quantum computing. The article is organized as a collection of sub-sections grouped into seven large thematic sections. Each sub-section is prepared by one or a group of authors and concludes with a brief description of the current challenges and the outlook of the further development of the research directions.

physics.app-ph