The variational quantum eigensolver (VQE) is a promising candidate that brings practical benefits from quantum computing. However, the required bandwidth in/out of a cryostat is a limiting factor to scale cryogenic quantum computers. We propose a tailored counter-based module with single flux quantum circuits in 4-K stage which precomputes a part of VQE calculation and reduces the amount of inter-temperature communication. The evaluation shows that our system reduces the required bandwidth by 97%, and with this drastic reduction, total power consumption is reduced by 93% in the case where 277 VQE programs are executed in parallel on a 10000-qubit machine.
@article{arxiv.2403.00363,
title = {SFQ counter-based precomputation for large-scale cryogenic VQE machines},
author = {Yosuke Ueno and Satoshi Imamura and Yuna Tomida and Teruo Tanimoto and Masamitsu Tanaka and Yutaka Tabuchi and Koji Inoue and Hiroshi Nakamura},
journal= {arXiv preprint arXiv:2403.00363},
year = {2024}
}