Andreev tunneling enhanced by Coulomb oscillations in superconductor-semiconductor hybrid Ge/Si nanowire devices

We explore the magneto-conductance of Ge/Si core/shell nanowire quantum dot devices contacted by superconducting leads. Significant magneto-conductance peaks around zero field are observed and show a periodic modulation with gate voltage as discrete states of the quantum dot are turned on- and off-resonance with the Fermi energy in the superconducting electrodes. The ability to create and control coherent transport in superconductor-semiconductor hybrid nanostructures allows for new opportunities in the study of various fundamental competing effects such as superconductivity and electron-electron interactions.