Superconducting materials can be used as very sensitive thermometers thanks to the strong dependence of their resistance on temperature near their critical temperature.
For this purpose, they need to be polarized in their superconducting to normal transition; that is why they are called Transition Edge Sensors or simply TESs. When coupled to suitable absorbers, they become one of the most sensitive radiation detectors and they are already in use in a wide range of applications (astrophysics, material science, quantum tecnologies,…).
In our group we have developed TESs based on Molibdenum/Gold layers a few nm thick which operate near 100mK. We integrated this sensors with Bismuth/Gold absorbers a few microns thick optimized for soft X-ray detection which can reach energy resolutions of 1/1000 in the range 1-10KeV. We are also developing novel absorber configurations for other wavelengths of interest for Quantum Information Technologies.
This work is funded by:
– The Spanish Ministerio de Ciencia, Innovación y Universidades-MICINN (project RTI2018-096686-B-C22)
– The European Space Agency (ESA).
– The European Union’s Horizon 2020 Programme under the AHEAD (Activities for the High-Energy Astrophysics Domain)