Large-scale Ising spin network based on degenerate optical parametric oscillators

TL;DR

This paper demonstrates a large-scale photonic Ising machine using over 10,000 degenerate optical parametric oscillators to simulate Ising spin models, enabling potential solutions to complex combinatorial problems.

Contribution

It introduces a scalable optical network of DOPOs for simulating Ising models, advancing photonic computing for optimization tasks.

Findings

Observed formation of spin domains in the DOPO network

Domain size diverges near the threshold, indicating low-temperature Ising behavior

Successfully simulated a 1D Ising model with optical coupling

Abstract

Simulating a network of Ising spins with physical systems is now emerging as a promising approach for solving mathematically intractable problems. Here we report a large-scale network of artificial spins based on degenerate optical parametric oscillators (DOPO), paving the way towards a photonic Ising machine capable of solving difficult combinatorial optimization problems. We generated >10,000 time-division-multiplexed DOPOs using dual-pump four-wave mixing (FWM) in a highly nonlinear fibre (HNLF) placed in a fibre cavity. Using those DOPOs, a one-dimensional (1D) Ising model was simulated by introducing nearest-neighbour optical coupling. We observed the formation of spin domains and found that the domain size diverged near the DOPO threshold, which suggests that the DOPO network can simulate the behavior of low-temperature Ising spins.