Fundamental Physics and Quantum Engineering at Ultralow Temperatures

Low temperatures provide a unique environment for measurements at extremely low noise levels and to study systems with low energy excitations. In recent years new technological developments allow to construct novel cryogenic detectors with unmatched resolution for single photons and massive particles that will enable new types of experiments that reach out for the neutrino mass and many other fundamentally important aspects of physics. We will discuss the principle of operation, the design and fabrication of such cryogenic detectors as well as results from recent applications ranging from to high resolution x-ray spectroscopy to the mass spectroscopy of molecular fragments.