A high-efficiency plug-and-play superconducting qubit network

TL;DR

This paper presents a high-efficiency, reconfigurable superconducting qubit network using a detachable cable interface, achieving near-threshold fault-tolerance operations and enabling scalable modular quantum computing.

Contribution

It introduces a novel fast pump scheme for high-fidelity inter-module connections in superconducting qubit networks, advancing modular quantum architecture.

Findings

Inter-module SWAP efficiency at 99% in under 100 ns

High-fidelity entanglement generation across modules

Operations near fault-tolerance error thresholds

Abstract

Modular architectures are a promising approach to scale quantum devices to the point of fault tolerance and utility. Modularity is particularly appealing for superconducting qubits, as monolithically manufactured devices are limited in both system size and quality. Constructing complex quantum systems as networks of interchangeable modules can overcome this challenge through `Lego-like' assembly, reconfiguration, and expansion, in a spirit similar to modern classical computers. First prototypical superconducting quantum device networks have been demonstrated. Interfaces that simultaneously permit interchangeability and high-fidelity operations remain a crucial challenge, however. Here, we demonstrate a high-efficiency interconnect based on a detachable cable between superconducting qubit devices. We overcome the inevitable loss in a detachable connection through a fast pump scheme, enabling inter-module SWAP efficiencies at the 99%-level in less than 100 ns. We use this scheme to generate high-fidelity entanglement and operate a distributed logical dual-rail qubit. At the observed ~1% error rate, operations through the interconnect are at the threshold for fault-tolerance. These results introduce a modular architecture for scaling quantum processors with reconfigurable and expandable networks.