Assembling future large-scale quantum computers out of smaller, specialized modules promises to simplify a number of formidable science and engineering challenges. One of the primary challenges in developing a modular architecture is in engineering high fidelity, low-latency quantum interconnects between modules. Here we demonstrate a modular solid state architecture with deterministic inter-module coupling between four physically separate, interchangeable superconducting qubit integrated circuits, achieving two-qubit gate fidelities as high as 99.1 ± 0.5% and 98.3 ± 0.3% for iSWAP and CZ entangling gates, respectively. The quality of the inter-module entanglement is further confirmed by a demonstration of Bell-inequality violation for disjoint pairs of entangled qubits across the four separate silicon dies. Having proven out the fundamental building blocks, this work provides the technological foundations for a modular quantum processor: technology which will accelerate near-term experimental efforts and open up new paths to the fault-tolerant era for solid state qubit architectures.

从较小的专用模块中组装未来的大规模量子计算机有望简化许多艰巨的科学和工程挑战。开发模块化架构的主要挑战之一是设计模块之间的高保真、低延迟量子互连。在这里，我们展示了一种模块化固态架构，在四个物理分离的、可互换的超导量子位集成电路之间具有确定性的模块间耦合，为 iSWAP 和 CZ 纠缠门实现了高达 99.1 ± 0.5% 和 98.3 ± 0.3% 的双量子位门保真度，分别。模块间纠缠的质量通过对跨越四个独立硅芯片的不相交纠缠量子位对的贝尔不等式违规的证明得到进一步证实。