JOSEPHSON JUNCTION READOUT FOR GRAPHENE-BASED SINGLE PHOTON DETECTOR

摘要

A detector for detecting single photons of infrared radiation. In one embodiment a waveguide configured to transmit infrared radiation is arranged to be adjacent a graphene sheet and configured so that evanescent waves from the waveguide overlap the graphene sheet. In some embodiments the waveguide is omitted and infrared light propagating in free space illuminates the graphene sheet directly. A photon absorbed by the graphene sheet from the evanescent waves heats the graphene sheet. The graphene sheet is coupled to the weak link of a Josephson junction, and a constant bias current is driven through the Josephson junction, so that an increase in the temperature of the graphene sheet results in a decrease in the critical current of the Josephson junction and a voltage pulse in the voltage across the Josephson junction. The voltage pulse is detected by the pulse detector.

主权项

1. A photon detector comprising:
a graphene sheet configured to absorb infrared electromagnetic waves and to undergo an increase in a temperature of the graphene sheet when a photon of the infrared electromagnetic waves is absorbed by the graphene sheet; a Josephson junction on the graphene sheet, the Josephson junction having a gap coupled to electrons of the graphene sheet; and a circuit connected to two contacts of the Josephson junction, the circuit configured to detect a decrease in a critical current of the Josephson junction, the decrease corresponding to the increase in the temperature of the graphene sheet.