Full counting statistics for superconducting quantum point contacts. A discussion of the impact of Andreev reflection on charge transfer in superconducting nanostructures

      Аннотация: The calculation of the full counting statistics (FCS) for quantum mechanical systems has attracted much attention in recent years. In this thesis the FCS for superconducting quantum point contacts have been calculated. Such quantum point contacts frequently occur in modern microelectronic devices, which exploit the special features of superconductors. The FCS for normal metal-superconductor and superconductor-superconductor contacts have been calculated using a generalized Keldysh formalism and the results have been compared to both experimental and theoretical results. The calculation of the FCS allows a precise understanding of the physical nature of charge transfer. Particularly doubled shot noise due to Andreev reflections was explained and the behaviour of the Josephson current for long measurement times was calculated. The obtained results are also valuable for the understanding of transport through quantum dots with superconducting leads.

Ключевые слова: Full counting statistics, superconductor, quantum point contact, Charge Transfer, Andreev reflection