Single Photon Detection with a Quantum Dot Transistor

Abstract

We propose and demonstrate a type of GaAs/AlGaAs modulation-doped field effect transistor (FET) which is sensitive to single photons. The FET contains a layer of InAs quantum dots formed using an in-situ, self-organising method, adjacent to the channel and separated from it by a thin AlGaAs barrier. Capture of a single photo-excited carrier by a quantum dot leads to a sizeable change in the source-drain current through the transistor, allowing the detection of a single photon. We show this is because the mobility of the electron channel is extremely sensitive to the charge trapped in the dots. This discovery may allow a new type of single photon detector to be developed which does not rely upon avalanche processes.

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

“…21 In devices in which the active region contains just a few hundred quantum dots, these interactions are strong enough to result in a small increase in the current through the channel when a photogenerated hole recombines with an electron trapped in a dot. 20 This response is detectable to temperatures of at least 77 K. 22 Detection of a single photon results therefore in a step in the source-drain current. In order to convert such steps into voltage peaks, we used the amplifier shown in Fig.…”

Nonlinear quantum optical computing via measurement

“…Current proposals for single photon sources include exciton quantum dots [ll-131, NV centres [14, 151, and surface acoustic wave devices [16]. Current proposals for detectors range from novel mesoscopic electronic devices [17], and supereonducting devices [ 181 to novel systems that use stimulated Raman scattering [19,201 and E I T [21].…”

Nano-scale quantum dot optical transducers by self-assembly

“…One critical component of nano-photonic integrated circuits will be nano-scale, super-sensitive single-photon detection and emission devices that require low-power. The unique opto-electronic properties of quantum dots (QDs) have been shown to improve performance in traditional devices like FET's [2], and photodetectors [3], but using quantum dots as individual devices has been largely unexplored. This is due, in part, to fabrication and scaling issues at the nano-scale.…”