Coherent quantum effects in networks of degenerate optical parametric oscillators

Recent experiments have shown that networks of degenerate optical parametric oscillators (OPOs) can encode and approximately solve combinatorial optimization problems. While these experiments presently operate in a regime well described by semiclassical models, it is interesting to ask whether coherent quantum effects such as entanglement or non-Gaussianity due to strong nonlinearities could qualitatively or quantitatively change the mechanism of the “solution” process. Using the SLH formalism for quantum input-output theory, we describe a general quantum network model for multiple degenerate OPOs connected via arbitrary beamsplitter couplings [1]. For a small number of oscillators, we numerically compare the solution process of this model in the mean-field limit against the extremely quantum regime where two-photon loss dominates linear loss in the individual OPOs.
[1] T. Onodera, E. Ng, and H. Mabuchi, doi: 10.1364/QIM.2017.QW3B.2 (2017).