Berlin 2015 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 109: Quantum dots and wires: Quantum communication and quantum information science
HL 109.2: Talk
Friday, March 20, 2015, 11:30–11:45, ER 164
Properties of excitonic V-shaped quantum dot systems for optical switches — •Yves Alexander Leier1, Dirk Mantei1, Jens Förstner1, Simon Gordon1, Dirk Reuter1, Andreas D. Wieck2, and Artur Zrenner1 — 1Center for Optoelectronics and Photonics Paderborn (CeOPP), Universität Paderborn, Warburger Straße 100, 33098 Paderborn, Germany — 2Ruhr-Universität Bochum, Universitätsstraße 150, Gebäude NB, 44780 Bochum, Germany
For the optical manipulation of a single quantum system, diverse approaches such as Rabi Oscillations and the Adiabatic Rapid Passage are well established techniques. To achieve an inversion as complete as possible we present a new possibility by examining a single quantum system with V-type three level scheme, a common ground state and two distinguishable and separately excitable transitions. Their sequential, pulsed excitation allows for the preparation of a robust, fault-tolerant and phase-insensitive inversion. In our contribution we demonstrate this concept, which is based on the polarization-selective excitation of a fine structure split exciton ground state in a single InGaAs quantum dot. We further propose a scheme for a robust optical switch, which is based on a related approach. A first horizontally polarized pi-pulse excites completely one of the fss-transitions of a quantum dot ensemble. Because of Pauli blocking a second pulse with orthogonal polarization can therefore not change the occupation of the quantum dot and passes the quantum dot without absorption.