Ultra-fast artificial neuron: generation of picosecond-duration spikes in a current-driven antiferromagnetic auto-oscillator

TL;DR

This paper proposes an antiferromagnetic auto-oscillator capable of generating ultra-short, picosecond-duration spikes that mimic neuronal action potentials, with potential applications in high-frequency neuromorphic computing.

Contribution

It introduces a novel AFM-based spike generator that produces ultrafast spikes with threshold behavior, suitable for neuromorphic and microwave signal processing.

Findings

Spike duration is several picoseconds, determined by magnetic anisotropy and damping.

Output can be a single spike or bursting pattern depending on control signals.

Spike generation requires surpassing a threshold amplitude of the control signal.

Abstract

We demonstrate analytically and numerically, that a thin film of an antiferromagnetic (AFM) material, having biaxial magnetic anisotropy and being driven by an external spin-transfer torque signal, can be used for the generation of ultra-short "Dirac-delta-like" spikes. The duration of the generated spikes is several picoseconds for typical AFM materials and is determined by the in-plane magnetic anisotropy and the effective damping of the AFM material. The generated output signal can consist of a single spike or a discrete group of spikes ("bursting"), which depends on the repetition (clock) rate, amplitude, and shape of the external control signal. The spike generation occurs only when the amplitude of the control signal exceeds a certain threshold, similar to the action of a biological neuron in response to an external stimulus. The "threshold" behavior of the proposed AFM spike generator makes possible its application not only in the traditional microwave signal processing but also in the future neuromorphic signal processing circuits working at clock frequencies of tens of gigahertz.