In our research subgroup on Quantum Dots we work with GaAs/AlGaAs or InP/InAsP quantum dots, towards three main projects: (1) developing robust excitation schemes to generate single or entangled photon pairs (2) generating time-bin entangled photons (3) designing and fabricating photonic cavity structures for improved photon extraction efficiency (read more...)
In our IGUANA project on Integrated Quantum Rangefinding we utilize the photon pairs produced in our Bragg-reflection waveguides for a quantum protocol for remote sensing. Inspired by quantum illumination it hinges on the thermal photon-pair probability distribution generated by parametric down-conversion. Different from quantum illumination, the protocol does not offer an improved signal-to-noise ratio, but perfect covertness guaranteed by the laws of quantum mechanics. (read more...)
In our UNIQORN project on Affordable Quantum Communication for Everyone we exploit the high effective optical nonlinearity of our AlGaAs waveguides and the low-loss polymer structures of our collaborators at the HHI in Berlin in a hybrid approach. Our Bragg-reflection waveguides act as a source of photon pairs at the telecom wavelength range, which are subsequently time-bin entangled in on-chip polymer michelson interferometers. (read more...)
In the D-A-CH project On-chip microlaser driven sources of indistinguishable photons for quantum networks we aim to combine the advantages of semiconductor quantum dots and Bragg-reflection waveguides in a single device. By exploiting the high optical nonlinearity of AlGaAs BRWs, we convert the single photons generated by an embedded quantum dot to telecom wavelengths via difference frequency generation. (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 Photonicstargets 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...)
Please find a detailed list of all our publications HERE
funding
The European Union supports our research activities related to quantum technology / quantum communications through it's Horizon 2020 research and innovation programme: Quantum Flagship
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 "On-chip microlaser driven sources of indistinguishable photons for quantum networks" (I-5061, together with Tobias Huber, University of Würzburg and Stephan Reizenstein, University of Berlin)
