Creating Electronic Oscillator-based Ising Machines without External Injection Locking

TL;DR

This paper introduces a novel electronic autaptic oscillator design that internally generates the necessary phase bipartition signal, enabling Ising machine implementation without external injection locking, and demonstrates its effectiveness in solving MaxCut problems.

Contribution

The work presents a new oscillator architecture that eliminates external second harmonic injection, simplifying Ising machine hardware and enhancing application-specific analog computing.

Findings

Successfully demonstrated phase bipartition in coupled EAOs

Achieved solution of MaxCut problem using the oscillator system

Eliminated need for external second harmonic injection

Abstract

Coupled electronic oscillators have recently been explored as a compact, integrated circuit- and room temperature operation- compatible hardware platform to design Ising machines. However, such implementations presently require the injection of an externally generated second-harmonic signal to impose the phase bipartition among the oscillators. In this work, we experimentally demonstrate a new electronic autaptic oscillator (EAO) that uses engineered feedback to eliminate the need for the generation and injection of the external second harmonic signal to minimize the Ising Hamiltonian. The feedback in the EAO is engineered to effectively generate the second harmonic signal internally. Using this oscillator design, we show experimentally, that a system of capacitively coupled EAOs exhibits the desired bipartition in the oscillator phases, and subsequently, demonstrate its application in solving the computationally hard Maximum Cut (MaxCut) problem. Our work not only establishes a new oscillator design aligned to the needs of the oscillator Ising machine but also advances the efforts to creating application specific analog computing platforms.