Fully heterogeneous prepare-and-measure quantum network for the next stage of quantum internet

The quantum internet promises unparalleled capabilities that are provably impossible with the classical internet. However, current quantum networks are often designed with dedicated systems for specified tasks, which hinders the openness and diversity of future quantum internet. To address these limitations, this work proposes a fully heterogeneous quantum network accompanied with several techniques. Our proposal allows users to access the network using any mainstream systems or even partial systems. The network also enables the execution of multiple distinct quantum tasks and provides opportunities for global optimization and cost-efficient design. A five-node quantum network featuring heterogeneous nodes has been implemented, demonstrating the superiority of our proposal through tasks such as quantum key distribution, quantum digital signature, quantum Byzantine agreement, and quantum conference. Notably, the experiment represents the first demonstration of multi-malicious node quantum Byzantine agreement in a quantum network. This work proposed a fully heterogeneous quantum network that connects diverse user systems and enables multiple quantum tasks. A software-defined quantum network structure is also proposed for coordinating network nodes and optimizing network performance. It paves the way for an open and versatile quantum internet.