Uncertainty quantification by ensemble learning is explored in terms of an application known from the field of computational optical form measurements. The application requires solving a large-scale, nonlinear inverse problem. Ensemble learning is used to extend the scope of a recently developed deep learning approach for this problem in order to provide an uncertainty quantification of the solution to the inverse problem predicted by the deep learning method. By systematically inserting out-of-distribution errors as well as noisy data, the reliability of the developed uncertainty quantification is explored. Results are encouraging and the proposed application exemplifies the ability of ensemble methods to make trustworthy predictions on the basis of high-dimensional data in a real-world context.

The EMPIR Project “Single and entangled photon sources for quantum metrology (SEQUME)” is set to start on June 1st, 2021, for a three-year funding period. The aim of SEQUME project is to develop bright entangled photon sources based on different application-oriented platforms and to exploit high-purity single-photon sources to demonstrate the quantum advantage achieved by using these sources for specific measurements. Making single-photon and entangled-photon sources, with the required performance parameters, more readily available, would be significant for the development of quantum technologies and the advancement of quantum-enhanced measurements. At PTB, Stefan Kück, Hristina Georgieva, Franziska Hirt, Marco Lopez, Sebastian Raupach, Andreas Schell, and Pablo Tieben are involved in the project. The project is coordinated by Stefan Kück at PTB and involves 8 NMIs and 10 Universities as partners.

The EMPIR Project “Quantum sensors for metrology based on single-atom-like device technology (QADeT)” is set to start on June 1st 2021 for a three-year funding period. The aim of the QADeT project is to realize single-atom-like systems (SALSs) in suitable materials, e.g. diamond, capable to perform nanoscale, high-sensitivity (electro-magnetic (EM) fields, temperature, stress, etc.) measurements.  Moreover, optimal methods to assess reproducibility in production and characterization of these systems and the host materials will be defined, paving the way for a standardization of the processes.