Quantum View of a Superconductor-Semiconductor Junction

Currently, electronic device technology is based mainly on semiconductors.  It first emerged in the middle of the 20:th: century and has improved ever since. Further technological advances including energy efficiency and information security might profit from exploiting quantum mechanical properties that are present in superconductors. The challenge is how to combine the two states and to make sure to get the best of both electrical worlds. A collaboration of researchers from Cornell and the Paul Scherrer Institute (PSI) in Switzerland grew thin films of the superconductor niobium nitride (NbN) on top of gallium nitride (GaN), a semiconductor and vital component in many optical and power electronics. The team measured the electronic properties of the two materials directly at their interface using soft-X-ray angle-resolved photoelectron spectroscopy (ARPES).