Lokaler und nichtlokaler Transport in Normalleiter-Supraleiter-Heterostrukturen

In this work the local and nonlocal conductance of mesoscopic normal-metal/superconductor hybrid structures has been measured. Subgap anomalies in both local and nonlocal conductance were observed. For the nonlocal conductance both positive and negative signs were found as a function of energy, hinting at a competition of crossed Andreev reflection and elastic cotunneling. The measured data suggests that the signals are caused by quantum mechanical interference rather than Coulomb interaction.