The narrow-band semiconductor PbTe superconducts with a Tc an order of magnitude greater than comparable low-density metals, but only when it is doped with valence-skipping elements.
The superconductor-insulator transition (SIT) is a quantum phase transition in disordered superconducting films that occurs at the point where two inherently two-dimensional topological phase transitions - charage and vortex Berezinskii-Kosterlitz-Thouless (BKT) transitions - terminate each other.
20 November 2015
The combination of superconductors and low-dimensional semiconductors embodies a rich, yet largely unexplored physics. In this hybrid system, macroscopic properties enforced by superconductivity can be controlled through electrically tunable microscopic degrees of freedom, inherent to a relatively small number of confined electrons.