| PhD Seminar

Name of the Speaker: Mr. Anirban Mukhopadhyay (EE19D022)
Guide: Prof. Anil Prabhakar
Venue: CSD-308 (Conference Hall)
Online meeting link: https://meet.google.com/fvb-vdce-yxr
Date/Time: 16th January 2025 (Thursday), 4:00 PM
Title: Spin Wave Active Ring Oscillators: From Nonlinear Dynamics to Computing Application

Abstract :

Nonlinear oscillators with delayed feedback have gained significant attention for their ability to demonstrate various nonlinear behaviours, such as soliton excitation, period doubling, and chaotic signal generation. Spin waves, small signal excitations propagating through magnetically saturated films, are promising candidates for developing nonlinear RF devices due to their highly tunable dispersive properties. In the initial stages of our work, we excited surface spin waves in a micrometre-thick yttrium iron garnet (YIG) film. We identified a few hundred MHz wide spin-wave passband. We then built a Spin Wave Active Ring Oscillator (SWARO) using the YIG film as a delay line. The interaction between the external RF drive and oscillator modes was investigated under different oscillator gain settings, drive frequencies, and amplitudes, leading to the observation of phenomena such as sideband generation, injection pulling, and injection locking in the spectral output of the driven oscillator [1]. Recent efforts have been directed towards leveraging the nonlinear dynamics of oscillators to process complex temporal information [2]. We demonstrated temporal pattern classification by analyzing the SWARO's envelope response to GHz drive signals modulated with distinct temporal sequences.

1. Mukhopadhyay, A. and Prabhakar, A., 2023, May. Non-linearities in Driven Spin-Wave Active Ring Oscillator. In 2023 IEEE International Magnetic Conference-Short Papers (INTERMAG Short Papers) (pp. 1-2). IEEE.

2. Appeltant, L., Soriano, M.C., Van der Sande, G., Danckaert, J., Massar, S., Dambre, J., Schrauwen, B., Mirasso, C.R. and Fischer, I., 2011. Information processing using a single dynamical node as a complex system. Nature Communications, 2(1), p.468.