title: Microwave photon counter based on Josephson junctions.
abstract: 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.
authors.affiliation: Department of Physics, University of Wisconsin, Madison, 53706, USA.
authors.forename: Y-F
authors.initials: YF
authors.lastname: Chen
authors.forename: D
authors.initials: D
authors.lastname: Hover
authors.forename: S
authors.initials: S
authors.lastname: Sendelbach
authors.forename: L
authors.initials: L
authors.lastname: Maurer
authors.forename: S T
authors.initials: ST
authors.lastname: Merkel
authors.forename: E J
authors.initials: EJ
authors.lastname: Pritchett
authors.forename: F K
authors.initials: FK
authors.lastname: Wilhelm
authors.forename: R
authors.initials: R
authors.lastname: McDermott