Development of microwave single photon detectors in lumped element and traveling wave architectures*

Detection of microwave photons is an important capability for superconducting quantum computing and microwave quantum optics. Promising single photon detectors have been demonstrated at microwave frequencies, but a single detector with high quantum efficiency, non-destructive detection, a low dark count rate, and broad detection bandwidth has thus far not been demonstrated. An enticing prospect is using the traveling-wave architecture, which has been used for broadband near-quantum-limited Josephson parametric amplifiers, for detection of discrete signals. Here we report progress towards experimental demonstration of single photon detection in lumped-element and traveling wave devices.