1,758 research outputs found
Rotating Accelerator-Mode Islands
The existence of rotating accelerator-mode islands (RAIs), performing
quasiregular motion in rotational resonances of order of the standard
map, is firmly established by an accurate numerical analysis of all the known
data. It is found that many accelerator-mode islands for relatively small
nonintegrability parameter are RAIs visiting resonances of different orders
. For sufficiently large , one finds also ``pure'' RAIs visiting
only resonances of the {\em same} order, or . RAIs, even quite small
ones, are shown to exhibit sufficient stickiness to produce an anomalous
chaotic transport. The RAIs are basically different in nature from
accelerator-mode islands in resonances of the ``forced'' standard map which was
extensively studied recently in the context of quantum accelerator modes.Comment: REVTEX, 31 pages (including 2 tables and 15 figures
Broadening of Andreev-Bound States in d_{x^2-y^2} superconductors
We investigate the broadening of the bound states at an interface of an
unconventional superconductor by bulk impurity scattering. We use the
quasiclassical theory and include impurity scattering in the Born and in the
unitarity limit. The broadening of bound states due to unitary scatterers is
shown to be substantially weaker than in the Born limit. We study various model
geometries and calculate the temperature dependence of the Josephson critical
current in the presence of these impurity-broadened bound states.Comment: 6 page including 7 figures, submitted to Phys. Rev.
Education and upbringing as sociocultural problem
The article is concerned with education and upbringing as sociocultural problem
Quasiparticle Interface States in Junctions Involving d-Wave Superconductors
Influence of surface pair breaking, barrier transmission and phase difference
on quasiparticle bound states in junctions with d-wave superconductors is
examined. Based on the quasiclassical theory of superconductivity, an approach
is developed to handle interface bound states. It is shown in SIS' junctions
that low energy bound states get their energies reduced by surface pair
breaking, which can be taken into account by introducing an effective order
parameter for each superconductor at the junction barrier. More interestingly,
for the interface bound states near the continuous spectrum the effect of
surface pair breaking may result in a splitting of the bound states. In the
tunneling limit this can lead to a square root dependence of a nonequilibrium
Josephson current on the barrier transmision, which means an enhancement as
compared to the conventional critical current linear in the transmission.
Reduced broadening of bound states in NIS junctions due to surface pair
breaking is found.Comment: 27 pages, Latex fil
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