Progress on coherent Ising machines constructed from optical parametric oscillators

We present a scalable optical processor with electronic feedback, based on networks of optical parametric oscillators. The design of our machine is inspired by adiabatic quantum computers, although it is not an AQC itself. Our prototype machine is able to find exact solutions of, or sample good approximate solutions to, a variety of hard instances of Ising problems with up to 100 spins and 10,000 spin-spin connections. We will show results from problems with continuous J_ij couplings and external-field h_i terms, as well as from a comparison with the D-Wave 2000Q quantum annealer on unweighted MAX-CUT problems. Reference: P.L. McMahon*, A. Marandi*, et al. Science 354, No. 6312, pp. 614-617 (2016).