105 research outputs found
Measurements of critical current diffraction patterns in annular Josephson junctions
We report systematic measurements of the critical current versus magnetic
field patterns of annular Josephson junctions in a wide magnetic field range. A
modulation of the envelope of the pattern, which depends on the junction width,
is observed. The data are compared with theory and good agreement is found.Comment: 4 pages, 5 figure
Whispering Vortices
Experiments indicating the excitation of whispering gallery type
electromagnetic modes by a vortex moving in an annular Josephson junction are
reported. At relativistic velocities the Josephson vortex interacts with the
modes of the superconducting stripline resonator giving rise to novel
resonances on the current-voltage characteristic of the junction. The
experimental data are in good agreement with analysis and numerical
calculations based on the two-dimensional sine--Gordon model.Comment: 5 pages, 5 figures, text shortened to fit 4 pages, correction of
typo
Experimental realization of a relativistic fluxon ratchet
We report the observation of the ratchet effect for a relativistic flux
quantum trapped in an annular Josephson junction embedded in an inhomogeneous
magnetic field. In such a solid state system mechanical quantities are
proportional to electrical quantities, so that the ratchet effect represents
the realization of a relativistic-flux-quantum-based diode. Mean static voltage
response, equivalent to directed fluxon motion, is experimentally demonstrated
in such a diode for deterministic current forcing both in the overdamped and in
the underdamped dynamical regime. In the underdamped regime, the recently
predicted phenomenon of current reversal is also recovered in our fluxon
ratchet.Comment: 4 pages, 6 figures. To appear in PHYSICA
Vacuum gauge from ultrathin MoS2 transistor
We fabricate monolayer MoS2 field effect transistors and study their electric
characteristics from 10^-6 Torr to atmospheric air pressure. We show that the
threshold voltage of the transistor increases with the growing pressure. Hence,
we propose the device as an air pressure sensor, showing that it is
particularly suitable as a low power consumption vacuum gauge. The device
functions on pressure-dependent O2, N2 and H2O molecule adsorption that affect
the n-doping of the MoS2 channel.Comment: 10 pages, 4 figure - conference pape
High anorectal malformation in a five-month-old boy: a case report
<p>Abstract</p> <p>Introduction</p> <p>Anorectal malformation, one of the most common congenital defects, may present with a wide spectrum of defects. Almost all male patients present within first few days of life.</p> <p>Case presentation</p> <p>A five-month-old baby boy of Indian origin and nationality presented with anal atresia and associated rectourethral prostatic fistula. The anatomy of the malformation and our patient's good condition permitted a primary definitive repair of the anomaly. A brief review of the relevant literature is included.</p> <p>Conclusion</p> <p>Delayed presentation of a patient with high anorectal malformation is rare. The appropriate treatment can be rewarding.</p
Experimental investigation of flux motion in exponentially shaped Josephson junctions
We report experimental and numerical analysis of expontentially shaped long
Josephson junctions with lateral current injection. Quasi-linear flux flow
branches are observed in the current-voltage characteristic of the junctions in
the absence of magnetic field. A strongly asymmetric response to an applied
magnetic field is also exhibited by the junctions. Experimental data are found
in agreement with numerical predictions and demonstrate the existence of a
geometry-induced potential experienced by the flux quanta in nonuniform width
junctions.Comment: 16 pg, 8 figures, Submitted in PRB March
Testing the Kibble-Zurek Scenario with Annular Josephson Tunnel Junctions
In parallel with Kibble's description of the onset of phase transitions in
the early universe, Zurek has provided a simple picture for the onset of phase
transitions in condensed matter systems, strongly supported by agreement with
experiments in He3. In this letter we show how experiments with annular
Josephson tunnel Junctions can and do provide further support for this
scenario.Comment: Revised version with correct formula for the Swihart velocity. The
results are qualitatively the same as with the previous version but differ
quantitatively. 4 pages, RevTe
Feasibility Study of High Temperature Superconducting Cables for Distribution Power Grids in Metropolises
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