Toward Terahertz Single-Photon Detection with Antenna-Coupled Graphene Josephson Junctions

Josephson junctions with graphene weak links (GJJs) have emerged as a promising platform for the detection of single photons. Combining the exceptionally small electronic heat capacity of graphene with the strongly temperature-dependent switching of current-biased Josephson junctions, these devices are capable of operating at low photon energies, with low dark count rates, and with high detection efficiencies when coupled to an appropriate resonant structure. Here we present measurements of two generations of antenna-coupled GJJ devices designed for operation at 0.8 THz using a filtered, calibrated blackbody lightsource. Such detectors could find important applications in future space-based far-infrared observatories and wide-bandwidth searches for dark matter axions.