Complex hybrid superconducting devices work thanks to the Josephson Junctions phenomenology. A Josephson Junction is a structure where two superconducting electrodes (S-S) are connected by a weak link, which is something that allows a transfer of the superconducting features from one electrode to the other [1-2].
In particular, the most peculiar properties of these junctions is that a cupercurrent can flow through them and such supercurrent depends on the electrodes superconducting phases. Typical weak links are tunnel junctions (SIS), where the S-electrodes are linked by an insulators barrier (I), proximized junctions (SNS), where the S-electrodes are linked by a normal metal (N) and Dayem bridges (ScS), where the S-electrodes are linked by a superconducting constrictions (c).

The remarkable aspect of the Josephson Junctions is that there are different application’s field for which their are suitables. First of all Josephson junctions are used as probing tools in more comlex devices, where they allow to control locally several electrical and thermal quantities, mainly for refrigeration and thermometer applications [3-4].
Furthermore Josephson Junctions are the main component of sensors and detectors, such as the Superconducting Quantum Interference Devices (SQUID)[5] and the Transition Edge Sensors (TES)[6].
Josephson Junction applications in detection are the point on which we want focus. In section “Superconducting Sensors” we explore deeper this aspect.

[1] M. Tinkham. Introduction to Superconductivity, 2nd ed. Dover books on Physics.
[2] A. Barone, G. Paternò. Physics and Applications of the Josephson Effect. Wiley.
[3] F. Giazotto et al., Rev. Mod. Phys. 81, 1351 (2009).
[4] A. Fornieri and F. Giazotto. Nature Nanotech 12, 944-952 (2017).
[5] J. Clarke and A. I. Braginski. The SQUID Handbook . Wiley.
[6] K.D. Irwin and G.C. Hilton. Transition-Edge Sensors. In Applied Physics, vol 99. Springer.