Title: Tunable artificial atoms: Strained quantum dots for single and entangled photon generations 

Speaker: Dr. Fei Ding (Deputy Head of Institute for Integrative Nanosciences, IFW Dresden, Germany)   

Time: Dec. 11, 2015 10:00AM 

Venue: No. 101 Meeting Room, IOS, CAS 

Abstract: Self-assembled semiconductor quantum dots (QDs), often referred to as artificial atoms, are among the most promising sources for quantum light (e.g. single photon and entangled photons). Compared to real atoms or any other sources, QDs have an undeniable advantage of being compatible with mature semiconductor technologies. Therefore semiconductor QD based quantum photonic devices are expected to play a crucial role in quantum information science.

Unlike real atoms, however, the physical properties of QDs are highly random. This is a serious problem for fabricating QDs based quantum devices where precise controls over the electronic and optical properties are needed. By embedding the QDs in stretchable nanomembranes, our group has developed a unique strain tuning technique to engineer the QDs. I will review our recent progresses (including 2 Nature Commun., 1 Nature Phys. 2 Phys. Rev. Lett. and 3 Nano Lett.) in terms of the realization of controllable quantum light sources. I will start with a wavelength tunable single photon source and in particular, in the form of a quantum light-emitting-diode. Then I will introduce a hybrid system where the single photon emission from artificial atoms (QDs) is coupled with real atoms (rubidium). Finally I will talk about our efforts in generating entangled photons with QDs. We have demonstrated an entangled light-emitting-diode with the fastest operation speed and highest yield ever reported. In a recent work we integrated the III-V sources with ultra-small footprints on silicon, and realized for the first time the wavelength tunable entangled photons with QDs.

Biography：Dr. Fei Ding is the Deputy Head of Institute for Integrative Nanosciences, IFW Dresden, Germany. He began the scientific career in 2004 in Institute of Semiconductor (CAS), under the supervision of Prof. Yonghai Chen and Prof. Zhanguo Wang. In 2006 he was selected as among the first candidates for the joint PhD program between Max-Planck-Society and Chinese Academy of Sciences. From 2006 to 2009 he studied in Max Planck Institute for Solid State Research Stuttgart (Department of Nobel Laureate Klaus von Klitzing). In 2007-2008 he spent a visit in Technical University of Delft (Group Leo Kouwenhoven), Netherlands. In 2010-2012, he was supported by the prestigious Marie Curie Fellowship and did the postdoctoral research in IBM Research Laboratory Zurich, Switzerland (birthplace of nanoscience, Nobel Prizes in 1986 and 1987). Since 2012 He is a senior staff member and leads the Nanophotonics group in IFW Dresden. He holds adjunct appointment as head of the Molecular Beam Epitaxy laboratory. Current research interests in his group include semiconductor materials, quantum light sources, nanophotonic devices, strained graphene and 2D transition metal dichalcogenides. He was honored with IBM Invention Achievement Award in 2012, IBM Patent Issuance Award (twice) in 2015, IFW-IIN Research Prize “for his pioneering works on strain tunable single photon sources” in 2014, and most recently, the first IFW Excellence Program for three years.