Gigahertz single-photon sources using coupled quantum wires and dots in microcavities

Research Topic

A surface acoustic wave can efficiently enhance the recombination lifetime and transport photo-excited electron-hole pairs along a semiconducting surface. The transport of carriers, and in particular the lifetimes of their spins during acoustic transport, can be enhanced by confining the carriers in quantum wires. This project aims at the study of the carrier and spin transport in quantum wire structures for quantum functionalities.


The main goal of the project is the creation of a single-photon source operating at GHz repetition rates, based on SAW-driven transport of charge and spin carriers that recombine to emit single photons with defined polarization. The single-photon source is made using lithographically patterned GaAs (113)A substrates with overgrown quantum wires (QWR) made by MBE and embedded in a Bragg microcavity. A first device constitutes partially to the milestone MS11. It is anticipated that the milestone will be complete by month 36.


Paul Helgers

Host: Paul-Drude-Institut für Festkörperelektronik Berlin

Scientific Background

During my studies in Applied Physics (TU Eindhoven), I got mainly fascinated by quantum physics and I chose to specialize on solid state physics. Throughout my studies I was introduced in various solid state research, mainly involving semiconductor physics and spintronics. For my master thesis I investigated the all-optical excitation of spin currents in ferromagnetic heterostructures.