Berlin 2015 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
HL: Fachverband Halbleiterphysik
HL 55: Quantum dots: Interaction with environment
HL 55.5: Talk
Wednesday, March 18, 2015, 16:00–16:15, EW 203
Near unity fidelity single hole spin preparation on picosecond timescales — •Tobias Simmet1, Per-Lennart Ardelt1, Kai Müller2, Alexander Kleinkauf1, Alexander Bechtold1, Gerhard Abstreiter1, and Jonathan J. Finley1 — 1Walter Schottky Institut and Physik-Department, Technische Universität München, Am Coulombwall 4, 85748 Garching, Germany — 2E. L. Ginzton Laboratory, Stanford University, Stanford, California 94305, USA
An isolated heavy-hole spin in optically active self-assembled InGaAs-GaAs quantum dots has emerged as a viable spin qubit, whereby the timescales for spin initialization, manipulation and read-out are crucial parameters. Here, we present a scheme for all optical, near fidelity heavy-hole spin initialization within ∼3ps by tunneling ionization from the optically prepared exciton state. By optimizing the thickness and Al-content of an AlGaAs tunneling barrier immediately adjacent to the quantum dot, we tailor the comparative tunneling escape rates of electron and heavy holes such that hole spins can be initialized with a fidelity >99% - even at zero magnetic fields - where optical spin initialization may be limited by electron-hole exchange interaction for the neutral exciton. Finally, we present how single heavy-hole spin storage and optical read-out via photocurrent can be optimized by time-gating the electric field using a spin storage device.