CMOS-compatible Ising and Potts Annealing Using Single Photon Avalanche Diodes

TL;DR

This paper introduces a CMOS-compatible annealing approach using single photon avalanche diodes (SPADs) that enables stochastic sampling for Ising and Potts models, with controllable temperature and practical CMOS fabrication.

Contribution

It demonstrates the design of CMOS-compatible SPAD-based Ising and Potts annealers that accurately sample from theoretical distributions, extending annealing capabilities.

Findings

SPADs enable effective stochastic state generation for annealing.

The method allows continuous temperature control in annealing processes.

The approach is compatible with standard CMOS manufacturing.

Abstract

Massively parallel annealing processors may offer superior performance for a wide range of sampling and optimization problems. A key component dictating the size of these processors is the neuron update circuit, ideally implemented using special stochastic nanodevices. We leverage photon statistics using single photon avalanche diodes (SPADs) and temporal filtering to generate stochastic states. This method is a powerful alternative offering unique features not currently seen in annealing processors: the ability to continuously control the computational temperature and the seamless extension to the Potts model, a $n$-state generalization of the two-state Ising model. SPADs also offer a considerable practical advantage since they are readily manufacturable in current standard CMOS processes. As a first step towards realizing a CMOS SPAD-based annealer, we have designed Ising and Potts models driven by an array of discrete SPADs and show they accurately sample from their theoretical distributions.