Photoconductance quantization in a single-photon detector

We have made a single-photon detector that relies on photoconductive gain in\na narrow electron channel in an AlGaAs/GaAs 2-dimensional electron gas. Given\nthat the electron channel is 1-dimensional, the photo-induced conductance has\nplateaus at multiples of the quantum conductance 2e$^{2}$/h. Super-imposed on\nthese broad conductance plateaus are many sharp, small, conductance steps\nassociated with single-photon absorption events that produce individual\nphoto-carriers. This type of photoconductive detector could measure a single\nphoton, while safely storing and protecting the spin degree of freedom of its\nphoto-carrier. This function is valuable for a quantum repeater that would\nallow very long distance teleportation of quantum information.\n