SAW-driven source of polarised single photons

Research Topic

Surface acoustic waves can confine and transport single electrons while maintaining their spin polarization. The acoustic transport of spin-polarized single electrons across a n-i-p junction followed by recombination with holes should give rise to the emission of single polarized photons at a rate equal to the SAW frequency.


The main goal of the project is to obtain a SAW-driven, polarised, single-photon source based on the acoustic transport of single electrons. The emission is obtained from the recombination of single electrons driven across an undoped n-i-p junction by surface acoustic waves into a region of holes. A proof-of-principle device constitutes the first milestone. I am trying to develop devices in which both electrons and holes are induced in an undoped GaAs/AlGaAs well by gates to form a lateral n-i-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.


Antonio Rubino

Host: University of Cambridge

Scientific Background

I obtained my Bachelor degree in Physics from the University of Salerno in 2013 working on Superconducting Nanowire Single-Photon detectors (SNSPDs) based on high temperature superconductors.
In July 2015, I completed a master degree in Physics at the same University, with a thesis on quantum optics at single-photon level. For the latter, I performed most of the experimental activity at Single Quantum BV and at Delft University of Technology, with Erasmus funding. I studied the single-photon emission and two photon interference from a nanowire quantum dot, the improvement of SNSPDs based on NbTiN, and the development of cold filters for the blackbody radiation.