High-Speed Phase-Based Computing

This work presents the utilization of rotary traveling wave oscillators (RTWOs) to implement an Ising machine. Ising machines utilizing ring oscillators have recently been demonstrated on silicon, for instance, for the solution of a max-cut problem. Rotary traveling wave oscillators scale better in frequency compared to ring oscillators, but have increased power consumption. Phase-based computing principles, implemented with the proposed RTWO-based Ising machines, are prime for high speed phase-based computation. The experiments reveal the proposed RTWO-based Ising machines provide significant reduction (5x) in runtime in the solution of the max-cut problem. The power dissipation is two orders of magnitude higher than the minuscule, low power ring-oscillators but RTWO-based Ising machines sub-linear increase with the demonstrated frequency increase from 2GHz to 32GHz for high speed phase-based computing. The accuracy of the solution is significantly improved as well, as demonstrated with respect to two of the D-Wave solvers (tabu and simulated annealing) acting as the baseline for ring oscillator and RTWO based Ising machines.