ﻻ يوجد ملخص باللغة العربية
This PhD thesis is divided in 6 chapters. In chapter 1 we introduce basic superconducting phenomena. Such as, the BCS theory, the Andreev reflection and the proximity effect, and the charge current transport in superconducting tunnel junctions. In chapter 2 we present the Keldysh nonequilibrium Green function formalism used to obtain the results of this thesis, together with clarifying examples corresponding to simple junctions. In chapter 3, the subgap transport properties of a SIF structure are studied. We devote chapter 4 to the study of thermal transport in superconducting nanohybrid structures. In chapter 5, we develop a general theory for the microwave-irradiated high-transmittance superconducting quantum point contact (SQPC), which consists of a thin constriction of superconducting material in which the Andreev states can be observed. The thesis concludes with a summary of the obtained results in chapter 6. The detailed derivation of the quasiclassical equations is presented in the appendix.
We describe the transport properties of mesoscopic devices based on the two dimensional electron gas (2DEG) present at the LaAlO$_3$/SrTiO$_3$ interface. Bridges with lateral dimensions down to 500~nm were realized using electron beam lithography. Th
The current-voltage characteristics of long and narrow superconducting channels are investigated using the time-dependent Ginzburg-Landau equations for complex order parameter. We found out that the steps in the current voltage characteristic can be
In this work, we review and expand recent theoretical proposals for the realization of electronic thermal diodes based on tunnel-junctions of normal metal and superconducting thin films. Starting from the basic rectifying properties of a single hybri
We have investigated the properties of the resistive state of the narrow superconducting channel of the length L/xi=10.88 on the basis of the time-dependent Ginzburg-Landau model. We have demonstrated that the bifurcation points of the time-dependent
We solve the coherent multiple Andreev reflection (MAR) problem and calculate current-voltage characteristics (IVCs) for Josephson SINIS junctions, where S are local-equilibrium superconducting reservoirs, I denotes tunnel barriers, and N is a short