Low temperature detectors are a class of detectors that leverage material properties at low temperature (normal- and super-conductivity, magnetization, ...) to detect radiation and measure its energy.  

Low temperature detectors can be broadly divided in two categories:

• equilibrium detectors which wait for all the deposited energy to have thermalized and measure temperature variations, i.e. changes in the thermodinamic equilibrium phonon energy distribution
• non-equilibrium detectors which do not wait for energy thermalization and are sensitive for example to athermal phonons created in the absorber or to changes in the density of quasi-particles in superconductors

Recent years have witnessed many exciting breakthroughs in neutrino physics.

In the Standard Model of Elementary Particles the neutrino ν is assumed to be not the same particle as the anti-neutrino  ν, i.e it is a Dirac particle. In many extensions to the Standard Model aiming to the Grand Unification of particle interactions and in theories of particle mass generation, the neutrino and the anti-neutrino turn out to be the same particle, i.e. the neutrino is a Majorana particle. The only available experimental probe to asses the actual nature of the neutrino is the search for the neutrinoless double beta decay.