ON-OFF Neuromorphic ISING Machines using Fowler-Nordheim Annealers

TL;DR

This paper presents NeuroSA, a neuromorphic Ising machine leveraging Fowler-Nordheim annealing to efficiently solve combinatorial optimization problems with high accuracy and without hyperparameter tuning.

Contribution

Introduction of NeuroSA, a neuromorphic architecture that maps simulated annealing dynamics onto integrate-and-fire neurons using Fowler-Nordheim tunneling for improved optimization performance.

Findings

Achieves solutions within 99% of state-of-the-art results

Surpasses current solutions for Max Independent Set benchmarks

Demonstrates feasibility on SpiNNaker2 platform

Abstract

We introduce NeuroSA, a neuromorphic architecture specifically designed to ensure asymptotic convergence to the ground state of an Ising problem using a Fowler-Nordheim quantum mechanical tunneling based threshold-annealing process. The core component of NeuroSA consists of a pair of asynchronous ON-OFF neurons, which effectively map classical simulated annealing dynamics onto a network of integrate-and-fire neurons. The threshold of each ON-OFF neuron pair is adaptively adjusted by an FN annealer and the resulting spiking dynamics replicates the optimal escape mechanism and convergence of SA, particularly at low-temperatures. To validate the effectiveness of our neuromorphic Ising machine, we systematically solved benchmark combinatorial optimization problems such as MAX-CUT and Max Independent Set. Across multiple runs, NeuroSA consistently generates distribution of solutions that are concentrated around the state-of-the-art results (within 99%) or surpass the current state-of-the-art solutions for Max Independent Set benchmarks. Furthermore, NeuroSA is able to achieve these superior distributions without any graph-specific hyperparameter tuning. For practical illustration, we present results from an implementation of NeuroSA on the SpiNNaker2 platform, highlighting the feasibility of mapping our proposed architecture onto a standard neuromorphic accelerator platform.