Prof. Guy Deutscher works on fundamental and applied aspects of superconductivity. He has focused on the properties of superconductors near the metal to insulator transition where, surprisingly, unusually strong superconductivity is observed in materials such as oxides and cermets, including high temperature superconductors and granular superconductors. Another research area is the development of superconducting tapes for power applications. The techniques used include thin film growth, transport, tunnelling, Tera-Herz and muon spectroscopy. Research achievements include the discovery that free spins are present in cermet films composed of nano-scale aluminum dots surrounded by oxide, consistent with a metal to insulator transition that is of the Mott type and a transition from conventional superconductivity to Bose Einstein condensation near the transition. Resonators based on such cermets have a large inductance and low losses, which is favorable for the design of elements for Quantum Computing. Another achievement is the development of superconducting tapes composed of cuprate thin films grown on sapphire ribbons, which are very promising as basic elements of fault current limiters that can improve network stability.