Abstract

Recent advances in controlling single carriers have shown that it is possible to transport single electrons back and forth between two quantum dots using surface acoustic waves (SAWs), with potential applications for quantum computation. We have developed devices in which both electrons and holes can be induced in an undoped GaAs/AlGaAs well by gates to form a lateral n-p junction. SAWs, generated by a transducer, travel in the n-region and collect electrons which are transported in the p-region where they recombine with the holes. If the stream is composed of single electrons, the recombination with holes should produce a stream of single photons. Furthermore, the recombination of spin-polarised electrons can generate circularly polarised photons, providing a method of spin readout in a quantum computer and a way for conversion of spin qubits into photon qubits. We are investigating the realisation of this potential polarised single-photon source; state of the progress and possible strategies will be presented.