Andreev Reflections And Transport Phenomena In Superconductors At The Interface With Ferromagnets And Normal Metals

Andreev Reflections and Transport Phenomena in Superconductors at the Interface with Ferromagnets and Normal Metals

Non-Linear Transport Properties of Hybrid Nanoelectronic Devices

The subject of this thesis is the study of hybrid nanoelectronic components involving superconductors or excitonic systems. The behavior of such electronic devices is relevant both for the miniaturization of electronics as well as for possible future on-chip quantum computation. In order to characterise them the cumulant generating function of charge transfer is calculated. First, quantum point contacts between (conventional und unconventional) superconductors, ferromagnets and semiconductors are investigated. The focus of interest are transport processes involving non-trivial correlated electronic states such as Cooper pairs, excitons or Majorana fermions. In the second part quantum impurities are included and the effects of onsite Coulomb and electron-phonon interaction are discussed. Using these results the possibility to witness entanglement in superconducting beamsplitters is demonstrated. The results are compared both to different theoretical approaches and experimental data.

Nanoscience and Engineering in Superconductivity

For emerging energy saving technologies superconducting materials with superior performance are needed. Such materials can be developed by manipulating the "elementary building blocks" through nanostructuring. For superconductivity the "elementary blocks" are Cooper pair and fluxon (vortex). This book presents new ways how to modify superconductivity and vortex matter through nanostructuring and the use of nanoscale magnetic templates. The basic nano-effects, vortex and vortex-antivortex patterns, vortex dynamics, Josephson phenomena, critical currents, and interplay between superconductivity and ferromagnetism at the nanoscale are discussed. Potential applications of nanostructured superconductors are also presented in the book.