810 research outputs found
RF-MEMS Switched Varactors for Medium Power Applications
In RF (Radio Frequency) domain, one of the limitations of using MEMS (Micro
Electromechanical Systems) switching devices for medium power applications is
RF power. Failure phenomena appear even for 500 mW. A design of MEMS switched
capacitors with an enhanced topology is presented in this paper to prevent it.
This kind of device and its promising performances will serve to fabricate a
MEMS based phase shifter able to work under several watts.Comment: Submitted on behalf of EDA Publishing Association
(http://irevues.inist.fr/handle/2042/16838
Magnetic-field-dependent quasiparticle energy relaxation in mesoscopic wires
In order to find out if magnetic impurities can mediate interactions between
quasiparticles in metals, we have measured the effect of a magnetic field B on
the energy distribution function f(E) of quasiparticles in two silver wires
driven out-of-equilibrium by a bias voltage U. In a sample showing sharp
distributions at B=0, no magnetic field effect is found, whereas in the other
sample, rounded distributions at low magnetic field get sharper as B is
increased, with a characteristic field proportional to U. Comparison is made
with recent calculations of the effect of magnetic-impurities-mediated
interactions taking into account Kondo physics.Comment: 4 pages, 3 figures, to be published in Physical Review Letter
Influence of Magnetic Field on Effective Electron-Electron Interactions in a Copper Wire
We have measured in a copper wire the energy exchange rate between
quasiparticles as a function of the applied magnetic field. We find that the
effective electron-electron interaction is strongly modified by the magnetic
field, suggesting that magnetic impurities play a role on the interaction
processes.Comment: latex anthore.tex, 8 files, 6 figures, 7 pages in: Proceedings of the
XXXVIth Rencontres de Moriond `Electronic Correlations: From Meso- to
Nano-physics' Les Arcs, France January 20-27, 2001 [SPEC-S01/027
Superconducting atomic contacts inductively coupled to a microwave resonator
We describe and characterize a microwave setup to probe the Andreev levels of
a superconducting atomic contact. The contact is part of a superconducting loop
inductively coupled to a superconducting coplanar resonator. By monitoring the
resonator reflection coefficient close to its resonance frequency as a function
of both flux through the loop and frequency of a second tone we perform
spectroscopy of the transition between two Andreev levels of highly
transmitting channels of the contact. The results indicate how to perform
coherent manipulation of these states.Comment: 14 pages, 10 figures, to appear in special issue on break-junctions
in JOPC
Complete genome sequence of Pseudomonas viridiflava CFBP 1590: isolated from diseased cherry in France
Pseudomonas viridiflava causes foliar and stem necrosis, as well as stem and root rot on a wide range of plants. We report here the first complete genome of a P. viridiflava strain, isolated from diseased tissue of a cherry tree
High-quality draft genome sequence of xanthomonas arboricola pv. juglandis CPBF 1521, isolated from leaves of a symptomatic walnut tree in Portugal without a past of phytosanitary treatment
Here, we report the draft genome sequence of Xanthomonas arboricola pv. juglandis CPBF 1521, isolated from symptomatic leaves of an ornamental walnut in a public site in Portugal without any record of phytosanitary treatment. This isolate may constitute a genomic reference of a wild-type strain in comparative genomics studies
Radio-Frequency Single-Electron Refrigerator
We propose a cyclic refrigeration principle based on mesoscopic electron
transport. Synchronous sequential tunnelling of electrons in a
Coulomb-blockaded device, a normal metal-superconductor single-electron box,
results in a cooling power of at temperature
over a wide range of cycle frequencies . Electrostatic work, done by the
gate voltage source, removes heat from the Coulomb island with an efficiency of
, where is the superconducting gap. The
performance is not affected significantly by non-idealities, for instance by
offset charges. We propose ways of characterizing the system and of its
practical implementation.Comment: 5 pages, 4 figures; corrected typos, language improve
Intensity of Coulomb Interaction between quasiparticles in diffusive metallic wires
The energy dependence and intensity of Coulomb interaction between
quasiparticles in metallic wires is obtained from two different methods:
determination of the temperature dependence of the phase coherence time from
the magnetoresistance, and measurements of the energy distribution function in
out-of-equilibrium situations. In both types of experiment, the energy
dependence of the Coulomb interaction is found to be in excellent agreement
with theoretical predictions. In contrast, the intensity of the interaction
agrees closely with theory only with the first method, whereas an important
discrepancy is found using the second one. Different explanations are proposed,
and results of a test experiment are presented.Comment: Submitted to Solid States Communication
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