Progress on coherent Ising machine

Abstract

“Ising machines,” which find low-energy states of the Ising model using physical experiments that emulates this model, are now drawing attention as a way to solve combinatorial optimization problems efficiently. A coherent Ising machine (CIM) is an optical Ising machine that uses the discretized phases of degenerate optical parametric oscillators as the Ising spins and employs the measurement-feedback to couple them. In this paper, we report the recent progress of the CIM research, including the realization and benchmarks of an ultra-large-scale CIM that can simulate a 100,000-spin Ising model with arbitrary spin-spin interactions.