Ising accelerator with a reconfigurable interferometric photonic processor

TL;DR

This paper presents a reconfigurable photonic Ising machine using a programmable photonic platform, capable of solving large-scale combinatorial optimization problems efficiently with high success rates.

Contribution

It introduces a novel, general-purpose programmable photonic Ising solver based on a hexagonal mesh platform, enabling scalable and reconfigurable optimization solutions.

Findings

Successfully solved benchmark problems including Max-Cut and ferromagnetic coupling.

Achieved over 80% success probability for problems with up to 50 spins.

Analyzed the impact of phase and coupling errors on performance.

Abstract

The general-purpose programmable photonic processors offer a scalable and reconfigurable solution for a wide range of RF and optical applications. Therefore, implementing photonic Ising machines using programmable processors leverages the advantages of high speed and parallelism, enabling efficient hardware acceleration for finding ground-state solutions to combinatorial optimization problems. In this work, we demonstrate a novel programmable photonic Ising solver based on a hexagonal mesh general-purpose programmable photonic platform. The integrated system allows reconfigurable matrix multiplication and computes the Hamiltonian iteratively using an annealing algorithm that facilitates spin updates and effectively searches for the ground state. As a proof of concept, we experimentally solve two benchmark optimization problems, a fundamental three-node ferromagnetic coupling problem with external bias that demonstrates nontrivial spin interactions, and a four-node Max-Cut problem with arbitrary coupling matrices. Furthermore, to establish a large-scale capability, we emulated Ising problems with sizes up to N = 50, achieving success probabilities exceeding 80\%. Additionally, we examined the impact of errors, such as phase and coupling, on the performance of the programmable photonic Ising machine. Our general-purpose photonic Ising machine paves the way for implementing large-scale, programmable architectures for solving optimization problems.