Helping today's quantum computers collaborate to tackle bigger problems

What is it about?

Modern quantum computers struggle to scale. Useful quantum algorithms require millions of qubits, but the largest chips of today have only thousands. One path forward is distributed quantum computing, which asks whether a network of interconnected quantum computers can work together to run such algorithms. The answer seems to depend on the algorithm. To make progress, we focus on a key primitive used in many important quantum algorithms: the Multi-Party SWAP test. This work develops COMPAS, the first distributed implementation of the Multi-Party SWAP test.

Featured Image

Photo by Scott Rodgerson on Unsplash

Photo by Scott Rodgerson on Unsplash

Why is it important?

Despite great promise, distributed quantum computing also incurs costs associated with coordinating many interconnected processors. Our architecture uses novel circuit constructions to reduce these costs. Furthermore, several important algorithms, including the recently developed Parallel Quantum Signal Processing algorithm, heavily rely on the Multi-Party SWAP test. Thus, our approach immediately lifts such algorithms to the distributed setting with minimal additional cost.