Entanglement is one of the most fascinating aspects of quantum mechanics and an indispensable resource for emerging quantum technologies. Properly engineered semiconductor quantum dots (QDs) are capable of emitting highly entangled photon pairs with ultra-low multi-pair emission probability even at maximum brightness. In this seminar, we will discuss the structural and optical properties of QDs based on the (Al)GaAs material platform followed by their use in entanglement-based quantum key distribution. For a proof of principle, the quantum key generation was performed between two buildings of the JKU campus at a rate of about 130 bits/s. By embedding the QDs in state-of-the-art photonic structures, key generation rates in the hundreds of Mbit/s range are at reach.

Prof. Armando Rastelli heads the Semiconductor Physics Division of the Johannes Kepler University of Linz, Austria since 2012. He obtained his PhD in Physics from the University of Pavia, Italy, in 2003. During his PhD he was research assistant at the ETH Zürich, Switzerland, and Marie-Curie-Fellow at the Technical University of Tampere, Finland. From 2003 to 2007 he was first Postdoc and then group leader at the Max-Planck-Institute of Stuttgart, Germany, and then at the Leibniz Institute of Dresden, Germany. In 2019 he was elected corresponding member of the Austrian Academy of Sciences. Throughout his career, he has been developing new methods to obtain, study, and control epitaxial quantum dots. The main current focus is on the optimization of quantum dots as quantum light sources for applications in photonic quantum technologies. He is coauthor of more than 230 peer-reviewed papers and has given more than 100 invited talks on the research activities of his group.