490 research outputs found
Massive liquid Ar and Xe detectors for direct Dark Matter searches
A novel experiment for direct searches of the Dark Matter with liquid argon
double-phase chamber with a mass of liquid Ar up to several hundred tons is
proposed. To suppress the b-, g- and n0- backgrounds, the comparison of
scintillation and ionization signals for every event is suggested. The addition
in liquid Ar of photosensitive Ge(CH3)4 or C2H4 and suppression of triplet
component of scintillation signals ensures the detection of scintillation
signals with high efficiency and provides a complete suppression of the
electron background. For the detection of photoelectrons and ionization
electrons, highly stable and reliable GEM detectors must be used.Comment: 8 pages, 2 figures, 1 tabl
Effects of fluctuations and Coulomb interaction on the transition temperature of granular superconductors
We investigate the suppression of superconducting transition temperature in
granular metallic systems due to (i) fluctuations of the order parameter
(bosonic mechanism) and (ii) Coulomb repulsion (fermionic mechanism) assuming
large tunneling conductance between the grains . We find the
correction to the superconducting transition temperature for 3 granular
samples and films. We demonstrate that if the critical temperature , where is the mean level spacing in a single grain the bosonic
mechanism is the dominant mechanism of the superconductivity suppression, while
for critical temperatures the suppression of
superconductivity is due to the fermionic mechanism.Comment: 12 pages, 9 figures, several sections clarifying the details of our
calculations are adde
Suppression of superconductivity in granular metals
We investigate the suppression of the superconducting transition temperature
due to Coulomb repulsion in granular metallic systems at large tunneling
conductance between the grains, . We find the correction to the
superconducting transition temperature for 3 granular samples and films. We
demonstrate that depending on the parameters of superconducting grains, the
corresponding granular samples can be divided into two groups: (i) the granular
samples that belong to the first group may have only insulating or
superconducting states at zero temperature depending on the bare intergranular
tunneling conductance , while (ii) the granular samples that belong to the
second group in addition have an intermediate metallic phase where
superconductivity is suppressed while the effects of the Coulomb blockade are
not yet strong.Comment: 4 pages, 3 figure
Discrete breathers in systems with homogeneous potentials - analytic solutions
We construct lattice Hamiltonians with homogeneous interaction potentials
which allow for explicit breather solutions. Especially we obtain exponentially
localized solutions for -dimensional lattices with .Comment: 10 page
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