A nonlinear magnonic nano-ring resonator

Abstract

The field of magnonics, which aims at using spin waves as carriers in data-processing devices, has attracted increasing interest in recent years. We present and study micromagnetically a nonlinear nanoscale magnonic ring resonator device for enabling implementations of magnonic logic gates and neuromorphic magnonic circuits. In the linear regime, this device efficiently suppresses spin-wave transmission using the phenomenon of critical resonant coupling, thus exhibiting the behavior of a notch filter. By increasing the spin-wave input power, the resonance frequency is shifted, leading to transmission curves, depending on the frequency, reminiscent of the activation functions of neurons, or showing the characteristics of a power limiter. An analytical theory is developed to describe the transmission curve of magnonic ring resonators in the linear and nonlinear regimes, and is validated by a comprehensive micromagnetic study. The proposed magnonic ring resonator provides a multi-functional nonlinear building block for unconventional magnonic circuits.

Electrical spectroscopy of the spin-wave dispersion and bistability in gallium-doped yttrium iron garnet

“…Such bistability could potentially be harnessed for microwave switching [24]. Foldover of the FMR and standing spin-wave modes has been studied for several decades [24][25][26], but foldover of propagating spin waves was only observed before in active feedback rings [27], spin-pumped systems [28] and magnonic ring resonators [29]. We show that we can characterize the foldover of propagating spin waves in Ga:YIG thin films using our spectroscopy technique.…”

“…The observed frequency shifts provide an extra knob for tuning the dispersion of spin waves. They give rise to strong non-linear microwave transmission between the striplines as a function of excitation power, which may provide opportunities for neuromorphic computing devices that simulate the spiking of artificial neurons above a certain input threshold [29,31].…”

Advances in Magnetics Roadmap on Spin-Wave Computing

“…A common example is a threshold function that lets the neuron "fire" an output signal only if a certain input threshold is exceeded. This functionality can be implemented using, e.g., nonlinear magnonic resonators [391] or directional couplers [325], [48]. Furthermore, spin waves possess an important property of short-term memory due to a significant delay time associated with their propagation in thin magnetic films.…”

Functional magnetic waveguides for magnonics

“…[1][2][3][4][5][6][7] It offers unique opportunities for wave-based technologies such as magnonics which is found to be promising for beyond-charge-based current semiconductor electronics. [8][9][10][11][12][13][14][15][16][17][18] It is widely acknowledged that magnonics is a promising candidate for future neuromorphic computing [19][20][21][22][23] and Boolean computing 10,[24][25][26] . In magnonics, the data are encoded in the amplitude or phase of the magnons which are quanta for spin wavesanalogous to photons for light waves in photonics.…”