High-accuracy Ising machine using Kerr-nonlinear parametric oscillators with local four-body interactions

TL;DR

This paper demonstrates that tuning detunings in a large array of Kerr-nonlinear parametric oscillators significantly improves the performance of an Ising machine based on four-body interactions, enabling scalable quantum optimization.

Contribution

It introduces a method to correct inhomogeneity in photon numbers by tuning detunings, enhancing large-scale implementation of KPO-based Ising machines.

Findings

Performance improves with detuning correction

Inhomogeneity reduction enhances scalability

Method applicable regardless of KPO array size

Abstract

A two-dimensional array of Kerr-nonlinear parametric oscillators (KPOs) with local four-body interactions is a promising candidate for realizing an Ising machine with all-to-all spin couplings, based on adiabatic quantum computation in the Lechner-Hauke-Zoller (LHZ) scheme. However its performance has been evaluated for only a few KPOs. By numerically simulating more KPOs, here we show that the performance can be dramatically improved by reducing inhomogeneity in photon numbers induced by the four-body interactions. The discrepancies of the photon numbers can be corrected by tuning the detunings of KPOs depending on their positions, without monitoring their states during adiabatic time evolution. This correction can be used independent of the number of KPOs in the LHZ scheme and thus can be applied to large-scale implementation.