Low-noise photon counting with a radio-frequency quantum-dot field-effect transistor

We present photon counting experiments with a single-photon detector based on a field-effect transistor gated by a layer of InAs quantum dots. A cryogenic radio-frequency amplifier is used to convert the photon-induced steps in the source-drain current of the transistor into voltage peaks. We measure a maximum photon detection efficiency of 0.14%, corresponding to internal quantum efficiency of 10%. The dark count rate is less than ${10}^{\text{−8}}\hspace{0.17em}{\mathrm{ns}}^{\text{−1}}$ when the efficiency is 0.045%.