APS Physics highlight

Our recent paper on single photon detection with graphene was published in the new journal Physical Review Applied. The paper has received an Editors suggestion and an APS Physics Synopsis news feed. The graphene single photon detector device sandwiches a sheet of graphene between two layers of superconducting material to create a Josephson junction. At low temperatures, and in the absence of photons, a superconducting current flows through the device. But the heat from a single photon is sufficient to warm the graphene, which alters the Josephson junction such that no superconducting current can flow. Thus photons can be detected by monitoring the device’s current. All of this works thanks to graphene’s unique band structure, which results in the material having a negligible electronic heat capacity. This property ensures that even a single low-energy photon can heat the material enough to block the superconducting current, and it enables heat to dissipate quickly, allowing the detector to rapidly reset. According to the team’s calculations, the device could detect individual infrared photons at a rate of up to a billion times per second and microwave photons at a rate of one million times per second. The team also suggests coupling photons into their device through waveguides and photonic cavities to make sure that no photon goes uncounted.