Looking into the early Universe with a solid-state device

Detecting relic neutrinos is a longstanding goal in fundamental physics. It is one of the predictions of the Standard Model that has not been yet confirmed. Additionally, it carries a photographic image of the early Universe, albeit from a much older epoch of neutrino decoupling.

The conventional approach to this problem is to search for the peak in the spectrum of electrons emitted in a beta-decay. Experimentally, this goal is extremely challenging as the required energy resolution is defined by the tiny neutrino masses (~10 meV).  While it seems possible to achieve a required energy resolution of the measuring apparatus, the intrinsic physics of the beta-emitting source imposes additional limitations. ??The current consensus is that sufficient statistics together with the clean spectrum could only be achieved if beta decayers are attached to a solid state substrate. If one wants to keep the energy resolution as high as the mass of the neutrino, one needs to account for the presence of the solid state environment.

This opens a whole new field of research in surface physics, both experimental and theoretical.  I will outline the main directions  and questions to be addressed  and their implications for the design of the full scale relic neutrino  experiment.