Организация, в которой проходила защита:
Twente University
Год защиты:2021
Аннотация:In this thesis, we develop a quantitative 2D model describing the distribution
of the supercurrent density and density of states in SN-N-NS type Josephson
junctions. This model is based on the self-consistent solution of the quasiclassical Usadel equations using the finite element method. We investigate
the influence of the proximity effect and the phase difference on the properties of the junction for various spatial dimensions and material parameters
of the S and N materials. We show that these results are consistent with
analytical solutions in the thin N layer limit and show logical behavior for
a large range of junction parameters. We extend our model to the case of
a junction with homogeneous in- and outflow current to investigate depairing effects in the superconducting electrodes. Furthermore, we extend our
model to ferromagnetic junctions by including the effect of an exchange field,
showing spin separation of the density of states and the occurrence of a 0-π
transition. These results may assist in improving the design of nanoscale
Josephson junctions for use in superconducting digital circuits.
