18,580 research outputs found
BCS theory of nodal superconductors
This course has a dual purpose. First we review the successes of the
weak-coupling BCS theory in describing new classes of superconductors
discovered since 1979. They include the heavy-fermion superconductors, high-Tc
cuprate superconductors, organic superconductors, Sr2RuO4, etc. Second, we
present the quasiclassical approximation introduced by Volovik, which we extend
to describe the thermodynamics and the thermal conductivity of the vortex state
in nodal superconductors. This approach provides the most powerful tool to
identify the symmetry of the energy gap function Delta(k) in these new
superconductors.Comment: 31 pages, 33 figure
New World of Gossamer Superconductivity
Since the discovery of the high-T cuprate superconductor
LaBaCuO in 1986 by Bednorz and M\"{u}ller, controversy regarding
the nature or origin of this remarkable superconductivity has continued.
However, d-wave superconductivity in the hole-doped cuprates, arising due to
the anti-paramagnon exchange, was established around 1994. More recently we
have shown that the mean field theory, like the BCS theory of superconductivity
and Landau's Fermi liquid theory are adequate to describe the cuprates. The
keys for this development are the facts that a)the pseudogap phase is d-wave
density wave (dDW) and that the high-T cuprate superconductivity is
gossamer (i.e. it exists in the presence of dDW).Comment: 6 pages, 4 figure
On the linearization of the generalized Ermakov systems
A linearization procedure is proposed for Ermakov systems with frequency
depending on dynamic variables. The procedure applies to a wide class of
generalized Ermakov systems which are linearizable in a manner similar to that
applicable to usual Ermakov systems. The Kepler--Ermakov systems belong into
this category but others, more generic, systems are also included
Generalized Hamiltonian structures for Ermakov systems
We construct Poisson structures for Ermakov systems, using the Ermakov
invariant as the Hamiltonian. Two classes of Poisson structures are obtained,
one of them degenerate, in which case we derive the Casimir functions. In some
situations, the existence of Casimir functions can give rise to superintegrable
Ermakov systems. Finally, we characterize the cases where linearization of the
equations of motion is possible
Computer Code System V. S. O. P. (99/11) Update 2011 of V.S.O.P(99)-Version 2009 CODE MANUAL
V.S.O.P. is a computer code system for the comprehensive numerical simulation of the
physics of thermal reactors. The application of the code implies processing of cross sections,
the set-up of the reactor and of the fuel element, neutron spectrum evaluation, neutron
diffusion calculation, fuel burnup, fuel shuffling, reactor control, and thermal hydraulics of
steady states and transients. The neutronics calculations can be performed in up to three
dimensions. Thermal hydraulics is restricted to gas-cooled reactors in two spatial dimensions.
Evaluation of fuel cycle costs over the reactor life time is made using the present worth
method. A broad description of the features of the code has been published in Ref. /1/
- …