409 research outputs found
Mesoscopic effects in superconductor-ferromagnet-superconductor junctions
We show that at zero temperature the supercurrent through the superconductor
- ferromagnetic metal - superconductor junctions does not decay exponentially
with the thickness of the junction. At large it has a random
sample-specific sign which can change with a change in temperature. In the case
of mesoscopic junctions the phase of the order parameter in the ground state is
a random sample-specific quantity. In the case of junctions of large area the
ground state phase difference is .Comment: 4 pages, 1 figur
Theory of disordered unconventional superconductors
In contrast to conventional s-wave superconductivity, unconventional (e.g. p
or d-wave) superconductivity is strongly suppressed even by relatively weak
disorder. Upon approaching the superconductor-metal transition, the order
parameter amplitude becomes increasingly inhomogeneous leading to effective
granularity and a phase ordering transition described by the Mattis model of
spin glasses. One consequence of this is that at low enough temperatures,
between the clean unconventional superconducting and the diffusive metallic
phases, there is necessarily an intermediate superconducting phase which
exhibits s-wave symmetry on macroscopic scales.Comment: 5 pages, 2 figure
Chiral Anomaly and Classical Negative Magnetoresistance of Weyl Metals
We consider the classical magnetoresistance of a Weyl metal in which the
electron Fermi surface possess nonzero fluxes of the Berry curvature. Such a
system may exhibit large negative magnetoresistance with unusual anisotropy as
a function of the angle between the electric and magnetic fields. In this case
the system can support a new type of plasma waves. These phenomena are
consequences of chiral anomaly in electron transport theory.Comment: 4 pages, 2 figure
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