8,520 research outputs found
Topology effects on the heat capacity of mesoscopic superconducting disks
Phase transitions in superconducting mesoscopic disks have been studied over
the H-T phase diagram through heat capacity measurement of an array of
independent aluminium disks. These disks exhibit non periodic modulations
versus H of the height of the heat capacity jump at the superconducting to
normal transition. This behaviour is attributed to giant vortex states
characterized by their vorticity L. A crossover from a bulk-like to a
mesoscopic behaviour is demonstrated. versus H plots exhibit
cascades of phase transitions as L increases or decreases by one unity, with a
strong hysteresis. Phase diagrams of giant vortex states inside the
superconducting region are drawn in the vortex penetration and expulsion
regimes and phase transitions driven by temperature between vortex states are
thus predicted in the zero field cooled regime before being experimentally
evidenced
Seller versus Broker: Timing of Promotion
Sellers and brokers may differ in preferred timing of costly promotion. Sellers with holding costs are anxious to sell. Sellers with showing costs want a slower approach. We find a standard listing contract where the broker chooses promotion timing can be efficient if sellers have no significant holding or showing costs. We then delineate the efficient listing contract provisions for duration and fee structure for sellers who have holding and/or showing costs.
Quantum Heating of a nonlinear resonator probed by a superconducting qubit
We measure the quantum fluctuations of a pumped nonlinear resonator, using a
superconducting artificial atom as an in-situ probe. The qubit excitation
spectrum gives access to the frequency and temperature of the intracavity field
fluctuations. These are found to be in agreement with theoretical predictions;
in particular we experimentally observe the phenomenon of quantum heating
Fine frequency shift of sigle vortex entrance and exit in superconducting loops
The heat capacity of an array of independent aluminum rings has been
measured under an external magnetic field using highly sensitive
ac-calorimetry based on a silicon membrane sensor. Each superconducting vortex
entrance induces a phase transition and a heat capacity jump and hence
oscillates with . This oscillatory and non-stationary behaviour
measured versus the magnetic field has been studied using the Wigner-Ville
distribution (a time-frequency representation). It is found that the
periodicity of the heat capacity oscillations varies significantly with the
magnetic field; the evolution of the period also depends on the sweeping
direction of the field. This can be attributed to a different behavior between
expulsion and penetration of vortices into the rings. A variation of more than
15% of the periodicity of the heat capacity jumps is observed as the magnetic
field is varied. A description of this phenomenon is given using an analytical
solution of the Ginzburg-Landau equations of superconductivity
Characterization of a two-transmon processor with individual single-shot qubit readout
We report the characterization of a two-qubit processor implemented with two
capacitively coupled tunable superconducting qubits of the transmon type, each
qubit having its own non-destructive single-shot readout. The fixed capacitive
coupling yields the \sqrt{iSWAP} two-qubit gate for a suitable interaction
time. We reconstruct by state tomography the coherent dynamics of the two-bit
register as a function of the interaction time, observe a violation of the Bell
inequality by 22 standard deviations after correcting readout errors, and
measure by quantum process tomography a gate fidelity of 90%
TeV gamma-rays from photo-disintegration/de-excitation of cosmic-ray nuclei
It is commonly assumed that high-energy gamma-rays are made via either purely
electromagnetic processes or the hadronic process of pion production, followed
by decay. We investigate astrophysical contexts where a third process (A*) may
dominate, namely the photo-disintegration of highly boosted nuclei followed by
daughter de-excitation. Starbust regions such as Cygnus OB2 appear to be
promising sites for TeV gamma-ray emission via this mechanism. A unique feature
of the A* process is a sharp energy minimum ~ 10 TeV/(T/eV) for gamma-ray
emission from a thermal region of temperature T. We also check that a diffuse
gamma-ray component resulting from the interaction of a possible extreme-energy
cosmic-ray nuclei with background radiation is well below the observed EGRET
data. The A* mechanism described herein offers an important contribution to
gamma-ray astronomy in the era of intense observational activity.Comment: To be published in Phys. Rev. Let
Pemahaman Tabib Etnis Tionghoa di Surabaya Mengenai Yīnyáng 泗水中医对阴阳之理解
Artikel ini bertujuan untuk mengetahui pemahaman tabib etnis Tionghoa di Surabaya mengenai yīnyáng dan cara penerapan konsep yīnyáng dalam profesi mereka.Teori yang menunjang terdiri atas teori keseimbangan yīnyáng merupakan dasar vitalitas kehidupan; keterkaitan konsep yīnyáng dengan keseimbangan bekerja, istirahat, dan bergerak. Artikel ini menggunakan metode penelitian kualitatif deskriptif dan teknik pengumpulan data dilakukan dengan cara wawancara semi terstruktur kepada masyarakat etnis Tionghoa Surabaya yang berprofesi sebagai tabib. Dari hasil penelitian diketahui bahwa para responden semuanya mengetahui konsep yīnyáng, sehingga semua responden menerapkan konsep keseimbangan yīnyáng dalam profesi mereka masing-masing
A 3-D Multilateration: A Precision Geodetic Measurement System
A system was designed with the capability of determining 1-cm accuracy station positions in three dimensions using pulsed laser earth satellite tracking stations coupled with strictly geometric data reduction. With this high accuracy, several crucial geodetic applications become possible, including earthquake hazards assessment, precision surveying, plate tectonics, and orbital determination
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