Superconducting circuits offer a scalable platform for the construction of large-scale quantum networks, where information can be encoded in multiple temporal modes of propagating microwaves. Characterization of such microwave signals with a method extendable to an arbitrary number of temporal modes with a single detector and demonstration of their phase-robust nature are of great interest. Here, we show the on-demand generation and Wigner tomography of a microwave time-bin qubit with superconducting circuit quantum electrodynamics architecture. We perform the tomography with a single heterodyne detector by dynamically switching the measurement quadrature independently for two temporal modes through the pump phase of a phase-sensitive amplifier. We demonstrate that the time-bin encoding scheme relies on the relative phase between the two modes and does not need a shared phase reference between sender and receiver.

超导电路为大规模量子网络的构建提供了可扩展的平台，其中信息可以以传播微波的多种时间模式进行编码。用可扩展到具有单个检测器的任意数量的时间模式的方法表征这种微波信号以及证明其相位鲁棒性非常令人感兴趣。在这里，我们展示了具有超导电路量子电动力学体系结构的微波时域量子位的按需生成和威格纳层析成像。我们通过一个相差放大器通过泵浦相位为两个时间模式动态地动态切换测量正交信号，从而使用单个外差探测器进行层析成像。