Network of Time-Multiplexed Optical Parametric Oscillators as a Coherent Ising Machine

TL;DR

This paper introduces a novel optical parametric oscillator network functioning as a coherent Ising machine, capable of solving complex combinatorial optimization problems efficiently at room temperature with high accuracy.

Contribution

The work presents the first implementation of a network of degenerate optical parametric oscillators as a physical Ising machine for solving NP-hard problems.

Findings

Successfully programmed an NP-hard Ising problem

Performed 1000 runs without computational errors

Operates at room temperature with configurable couplings

Abstract

Finding the ground states of the Ising Hamiltonian [1] maps to various combinatorial optimization problems in biology, medicine, wireless communications, artificial intelligence, and social network. So far no efficient classical and quantum algorithm is known for these problems, and intensive research is focused on creating physical systems - Ising machines - capable of finding the absolute or approximate ground states of the Ising Hamiltonian [2-6]. Here we report a novel Ising machine using a network of degenerate optical parametric oscillators (OPOs). Spins are represented with above-threshold binary phases of the OPOs and the Ising couplings are realized by mutual injections [7]. The network is implemented in a single OPO ring cavity with multiple trains of femtosecond pulses and configurable mutual couplings, and operates at room temperature. We programed the smallest non-deterministic polynomial time (NP)- hard Ising problem on the machine, and in 1000 runs of the machine no computational error was detected.