Semiconductor quantum dots for quantum photonics applications

Semiconductor quantum dots (QDs) obtained by epitaxial growth are regarded as one of the most promising solid-state sources of triggered single and entangled photons for applications in emerging quantum communication and photonic quantum-information-processing.

In this talk, I will introduce the “features and bugs” of QDs in view of their potential applications, followed by a presentation of some of our recent results. In particular, I will focus on GaAs QDs in AlGaAs matrix [1,2], which show a unique combination of appealing features: fast radiative rates of ~5 GHz, capability of generating near perfectly entangled photon pairs [3] with excellent indistinguishability and ultralow multiphoton emission probability [4], as well as wavelength matched to the high-sensitivity range of silicon-based single-photon detectors and optical transitions of Rubidium atoms [5]. I will also show that some of the QD “bugs” can be fixed by integrating them onto piezoelectric actuators [6-7]. Strain provided by such actuators is a powerful tool to bring the emission energy of separate dots into resonance [8], to restore broken symmetries [7], and also to change the polarization properties of the emitted photons [9]. I will conclude by discussing the open challenges.