12 research outputs found
Pinhole junctions in d-wave superconductors
We present a self consistent treatment of pinhole junctions in
superconductors. The current-phase relation is studied at different
temperatures and at different angles between the crystal -axis
and the junction (surface) normal. We show that the critical current of a
junction can be reduced by pair-breaking effects at the separation. We also
study the Josephson energy of a pinhole as a function of the phase difference
across the junction. In particular are mapped the positions of the energy
minima at different temperatures as functions of
(), the crystal orientations of the left and right
superconductors. With decreasing temperature there is an increasing range of
crystal orientations where varies continuously from 0 to .Comment: 14 pages, RevTeX, 11 PostScript figures, accepted for publication in
Physica
Binary Tree Approach to Scaling in Unimodal Maps
Ge, Rusjan, and Zweifel (J. Stat. Phys. 59, 1265 (1990)) introduced a binary
tree which represents all the periodic windows in the chaotic regime of
iterated one-dimensional unimodal maps. We consider the scaling behavior in a
modified tree which takes into account the self-similarity of the window
structure. A non-universal geometric convergence of the associated superstable
parameter values towards a Misiurewicz point is observed for almost all binary
sequences with periodic tails. There are an infinite number of exceptional
sequences, however, which lead to superexponential scaling. The origin of such
sequences is explained.Comment: 25 pages, plain Te