Microwave Photon Counter Based on Josephson Junctions
Yung‐Fu Chen, David J. Hover, S. Sendelbach, Leon N Maurer, Seth Merkel, Emily Pritchett, Frank K. Wilhelm, R. McDermott · Physical Review Letters · 2011
We describe a microwave photon counter based on the current-biased Josephson junction. The junction is tuned to absorb single microwave photons from the incident field, after which it tunnels into a classically observable voltage state. Using two such detectors, we have performed a microwave version of the Hanbury Brown-Twiss experiment at 4 GHz and demonstrated a clear signature of photon bunching for a thermal source. The design is readily scalable to tens of parallelized junctions, a configuration that would allow number-resolved counting of microwave photons.