Carrier Transport Through a Superconductor/Normal-Conductor Interface

Abstract

In this chapter the carrier transport through the simplest structure, a super-conductor/semiconductor bilayer is, discussed. A detailed understanding of this key structure is essential for the study of more sophisticated structures, i.e. Josephson junctions or three-terminal structures, as presented in the following chapters. First, we shall introduce Andreev reflection as a fundamental mechanism related to transport through a superconductor/semiconductor interface. Next, the Blonder-Tinkham-Klapwijk (BTK) model [46] is explained, which treats the carrier transport through a non-ideal interface with a barrier in between. Because of its simplicity, the BTK model is referred to frequently to describe transport through a superconductor/semiconductor interface. However, the experimental results obtained on single interfaces suggest that some extensions, e.g. the inclusion of the proximity effect, are necessary in order to obtain a better theoretical description of the experimental findings.