projects

In our project on quantum dots we investigate a variety of types of quantum dots. The material is mostly InAs on either GaAs or in InP nanowires. Based on these dots we want to develop single photon and entangled photon pair sources. Further we are studying the interfacing of quantum dot photons to photons generated in parametric down-conversion. (read more...)

In our project on Entangled Photon Pairs from Semiconductor Waveguides we are able to exploit the large optical nonlinearities that some semiconductors (e.g. GaAs) offer. Phase-matching is difficult and traditional quasi-phase-matching techniques, like periodic poling don't work in semiconductors. So far the most successful approach uses Bragg waveguides. (read more...)

In our project on microcavity polaritons we trap light in special semiconductor nanostructures to make it strongly interacting with electronic states in the GaAs-AlGaAs hetero structure. We investigate the opportunities to utilize these half-light, half-matter quasi-particles for generation of non-classical polariton states and quantum states of light (read more...)

Starting from a triple-slit experiment we are investigating higher-order, i.e. genuine Multi-Path Interferences for possible deviations from quantum mechanics as well as the possibility to represent quantum mechanics by hypercomplex (e.g. quaternion) numbers instead of complex ones. For this purpose we have a five-path interferometer and measure the ration of higher-order to regular interference. (read more...)

Our project on many-particle interference takes a look at interference phenomena beyond single particles or waves. For multiple identical particles, another layer of interference arises due to their exchange symmetry. We investigate conditions for fully destructive interference theoretically as well as experimentally via multi-photon states from nonlinear crystals or quantum dots. (read more...)

Our SFB project P14 - Integrated Quantum Photonics targets optical quantum information processing on a highly integrated III-V semiconductor platform. This platform is extremely versatile, because it goes beyond just passive elements but hosts single photon and photon pair sources based on quantum dots and on spontaneous parametric down-conversion. (read more...)

collaborations

Buchleitner Andreas, University of Freiburg, Germany

Höfling Sven & Schneider Christian, University of Wuerzburg, Germany

Imamoglu Atac, ETH Zuerich, Switzerland

Jenewein Thomas, IQC and University of Waterloo, Ontario, Canada

Predojevic Ana, Stockholm University, Sweden

Pullerits Tönu, Lund University, Sweden

Rastelli Armando, Johannes Kepler University Linz, Austria

Reitzenstein Stefan & Laiho Kaisa, Technical University Berlin, Germany

Szameit Alexander, University of Rostock, Germany

publications

Please find a detailed list of all our publications HERE

funding

• The Canadian Institute for Advanced Research   supports all our research activities related to quantum communications and through its Quantum Information Science Program.

• The European Union   supports our research activities related to quantum technology / quantum communications through it's Horizon 2020 research and innovation programme: Quantum Flagship

•  The Austrian Science Fund    funds our work through the following projects..
  
  • SFB "Beyond-C", project "P14 - Integrated Quantum Photonics" (F-07114, together with IST Austria, University of Vienna, OEAW, Max-Planck-Institute for Quantum Optics in Garching, Germany)
  • D-A-CH project "Polariton-based single-photon sources" (I-2199, together with Christian Schneider, University of Würzburg and Atac Imamoglu, ETH Zurich)
  • D-A-CH project "Multi-Path Interference Tests of Quantum Mechanics" (I-2562, together with Dr. Caslav Brukner, University of Vienna and Dr. Alexander Szameit, University of Rostock, Germany)
  • Doctoral Program "Atoms, Light and Molecules" (W-1259, Speaker: R. Wester)
  • Project "Many-particle interference in symmetric scattering scenarios" (P-30459, Dr. Robert Keil, together with Armando Rastelli, University of Linz)

 past funding

• The Austrian Science Fund (FWF) funded our D-A-CH project "Integrated Sources of Entangled and Indistinguishable Photons" (I-2065, toegther with Christian Schneider, University of Würzburg and Stephan Reitzenstein, TU Berlin, 2015-2018)
• The Austrian Science Fund (FWF) funded the work of Dr. Robert Keil on "Fundamental tests of quantum mechanics in optical waveguides" (Lise-Meitner fellowship, M-01849, 2015-2017)
• The Austrian Science Fund (FWF) funded the work of Dr. Ana Predojevic on "Entanglement from Quantum Dots" (Elise-Richter fellowship, V-00375, 2014-2016)
• The European Research Council funded our project "Entanglement from Semiconductor Nanostructures"  to investigate Quantum Dots and Microcavity Exciton-Polaritons as sources for entangled photon pairs (ERC Starting Grant, Project No. 257531, 2011-2015)
• The Austrian Science Fund (FWF) funded our work on polariton entanglement through the standalone project "Polariton Entanglement" (P-22979-N16, 2011-2015, together with G. Strasser, TU Vienna).
• The Foundational Questions Institute (FQXi) funded our work on multipath interference through their Large Grant "Higher-order Interferences and Time in Alternatives to Quantum Theory" (2011-02814, 2011-2013, together with C. Brukner, University of Vienna).
• The Austrian Science Fund (FWF) funded the work of Dr. Ana Predojevic on "Semiconductor Quantum Dot Photonic Interface" (Lise-Meitner fellowship, M-01243 , 2010-2012)