A spinwave Ising machine

TL;DR

This paper introduces a spin-wave-based Ising machine using YIG film that efficiently solves MAX-CUT problems in microseconds with low power, showcasing a promising approach for high-speed optimization hardware.

Contribution

The authors demonstrate a novel spin-wave Ising machine with real-time dynamics, achieving fast problem solving and low energy consumption using microwave components and YIG film.

Findings

Solves MAX-CUT problem in less than 4 microseconds

Consumes only 7 microjoules of energy

Potential for further miniaturization and scalability

Abstract

We demonstrate a spin-wave-based time-multiplexed Ising Machine (SWIM), implemented using a 5 $\mu$m thick Yttrium Iron Garnet (YIG) film and off-the-shelf microwave components. The artificial Ising spins consist of 34--68 ns long 3.125 GHz spinwave RF pulses with their phase binarized using a phase-sensitive microwave amplifier. Thanks to the very low spinwave group velocity, the 7 mm long YIG waveguide can host an 8-spin MAX-CUT problem and solve it in less than 4 $\mu$s while consuming only 7 $\mu$J. Using a real-time oscilloscope, we follow the temporal evolution of each spin as the SWIM minimizes its energy and find both uniform and domain-propagation-like switching of the spin state. The SWIM has the potential for substantial further miniaturization, scalability, speed, and reduced power consumption, and may become a versatile platform for commercially feasible optimization problem solvers with high performance.