Download Triggered entangled photon-pairs from single quantum dots and

Non-classical and stimulated photon emission
processes from semiconductor nanostructures
Peter Michler
Institut für Halbleiteroptik und Funktionelle Grenzflächen, Universität Stuttgart
During the last few years remarkable progress has been achieved in the
development of single and coupled semiconductor quantum dots and high-quality
micro-cavities which might open the way for new applications in the field of
quantum information processing.
Here we demonstrate triggered polarization-entangled photon pair emission from
a single quantum dot up to temperatures of 30 K. The fidelity of the maximally
entangled state decreases only little from 72 % at 5 K to 68 % at 30 K. This is
especially encouraging for future implementations in practical devices.
We report inter-dot electron coupling on laterally coupled (In,Ga)As QDs. The
degree of tunnel coupling can be controlled by applying a static electric field
along the quantum dot molecule (QDM) axis. By applying a voltage the electron
probability can be reversibly shifted to either QD, and the QDM can be used to
create a wavelength-tunable single photon emitter.
Furthermore, we present systematic first-order coherence measurements of
high-β quantum-dot micro-pillar lasers. Our results show a strong influence of
the β-factor on the coherence properties of the emitted light and reveal a
correlation of the coherence length with the spontaneous emission coupling β.