Superconducting Devices
Superconductivity is one of most fascinating manifestation of quantum effects on macroscopic scales, when at a certain low temperature a huge ensemble of electrons spontaneously forms a single whole called superconducting condensate described by a common wavefunction.
Despite many spectacular laboratory level demonstrations, in the ‘big world’ superconducting devices with rare exceptions (e.g., MRI magnets and filters for cellular phone stations) still struggle to occupy a significant market, but they have long been indispensable in precision metrology. In particular, large arrays of Josephson junctions provide a linear relation between voltage and frequency for the voltage standard and superconducting quantum interference devices, SQUIDs, are used in Cryogenic Current Comparators for precise measurements of the current ratios.
The exploratory research projects below aim to broaden the scope of metrological applications of Josephson devices to precision current standards, single photon detectors, single spin flip magnetometers, and emitters of electromagnetic radiation in the difficult terahertz frequency range.