Inductively coupled Josephson junctions: a platform for rich neuromorphic dynamics

TL;DR

This paper explores the nonlinear dynamical behaviors of inductively coupled Josephson junctions, demonstrating their potential for rich neuromorphic computing through phenomena like spiking, synchronization, and bursting dynamics.

Contribution

It introduces a detailed analysis of neuromorphic dynamics in coupled Josephson junctions, including a novel mechanism for bursting behavior not previously described.

Findings

Identification of saddle-node off invariant cycle bifurcation leading to spiking

Observation of excitability type 2 in the system

Reproduction of bursting dynamics with a new underlying mechanism

Abstract

Josephson junctions (JJs) are by nature neuromorphic hardware devices capable of mimicking excitability and spiking dynamics. When coupled together or combined with other superconducting elements, they can emulate additional behaviors found in biological neurons. From a technological point of view, JJ-based neuromorphic systems are particularly appealing since they present THz-speed processing and they operate with near-zero power dissipation. In this work we study a system of inductively coupled JJs and focus on the nonlinear dynamical aspects of its neurocomputational properties. In particular, we report on spiking behavior related to a saddle-node off invariant cycle bifurcation and excitability type 2, synchronization, first spike latency effects, and multistability. Special emphasis is placed on the bursting dynamics the system is capable of reproducing, and a new underlying mechanism is proposed beyond the approach followed in prior works.