标题： 一种抗热噪声的微波量子网络跨越 4 K 显示英文标题

标题： A thermal-noise-resilient microwave quantum network traversing 4 K

摘要： 微波频率的量子通信一直受到微波光子对热噪声敏感的制约，阻碍了它们在可扩展量子网络中的应用。 在这里，我们展示了一个抗热噪声的微波量子网络，该网络通过一个4 K热化铌钛传输线在两个超导量子比特之间建立了相干耦合。 通过将通信信道过度耦合到10 mK的冷负载上，我们通过辐射冷却将信道的有效热占据度抑制到0.06个光子——比环境热噪声低两个数量级。 然后我们解耦冷负载，并在信道重新热化的过程中快速传输微波量子态，实现了58.5%的状态传输保真度和52.3%的贝尔纠缠保真度，两者都超过了经典通信阈值。 我们的架构克服了微波量子系统在温度兼容性方面的障碍，为分布式量子计算提供了可扩展的框架，并使能与更高温半导体或光子平台的混合量子网络。 显示英文摘要

摘要： Quantum communication at microwave frequencies has been fundamentally constrained by the susceptibility of microwave photons to thermal noise, hindering their application in scalable quantum networks. Here we demonstrate a thermal-noise-resilient microwave quantum network that establishes coherent coupling between two superconducting qubits through a 4 K thermalized niobium-titanium transmission line. By overcoupling the communication channel to a cold load at 10 mK, we suppress the effective thermal occupancy of the channel to 0.06 photons through radiative cooling -- a two-order-of-magnitude reduction below ambient thermal noise. We then decouple the cold load and rapidly transfer microwave quantum states through the channel while it rethermalizes, achieving a 58.5% state transfer fidelity and a 52.3% Bell entanglement fidelity, both exceeding the classical communication threshold. Our architecture overcomes the temperature-compatibility barrier for microwave quantum systems, providing a scalable framework for distributed quantum computing and enabling hybrid quantum networks with higher-temperature semiconductor or photonic platforms.