A tunable macroscopic quantum system based on two fractional vortices

We propose a tunable macroscopic quantum system based on two fractional vortices. Our analysis shows that two coupled fractional vortices pinned at two artificially created \kappa\ discontinuities of the Josephson phase in a long Josephson junction can reach the quantum regime where coherent quantum oscillations arise. For this purpose we map the dynamics of this system to that of a single particle in a double-well potential. By tuning the \kappa\ discontinuities with injector currents we are able to control the parameters of the effective double-well potential as well as to prepare a desired state of the fractional vortex molecule. The values of the parameters derived from this model suggest that an experimental realisation of this tunable macroscopic quantum system is possible with today's technology.Comment: We updated our manuscript due to a change of the focus from qubit to macroscopic quantum effect

Mancha-foliar-marrom da Nogueirapecã: Identificação e Manejo da Doença nos Pomares do Sul do Brasil.

bitstream/item/206988/1/COMUNICADO-TECNICO-373.pd

The Geometric Spreading of Coronal Plumes and Coronal Holes

The geometric spreading in plumes and in the interplume region in coronal holes is calculated, using analytic and numerical theoretical models, between 1.0 and 5.0 solar radius. We apply a two-scale approximation that permits the rapid local spreading at the base of plumes (f(sub t)) to be evaluated separately from the global spreading (f(sub g)) imposed by coronal hole geometry. We show that f(sub t) can be computed from a potential-field model and f(sub g) can be computed from global magnetohydrodynamic simulations of coronal structure. The approximations are valid when the plasma beta is mail with respect to unity and for a plume separation small with respect to a solar radius

Possible observation of parametrically amplified coherent phasons in K0.3MoO3 using time-resolved extreme-ultraviolet ARPES

We use time- and angle-resolved photoemission spectroscopy (tr-ARPES) in the Extreme Ultraviolet (EUV) to measure the time- and momentum-dependent electronic structure of photo-excited K0.3MoO3. Prompt depletion of the Charge Density Wave (CDW) condensate launches coherent oscillations of the amplitude mode, observed as a 1.7-THz-frequency modulation of the bonding band position. In contrast, the anti-bonding band oscillates at about half this frequency. We attribute these oscillations to coherent excitation of phasons via parametric amplification of phase fluctuations.Comment: 4 figure

A detailed study of the rise phase of a long duration X-ray flare in the young star TWA 11B

We analyzed a long duration flare observed in a serendipitous XMM-Newton detection of the M star CD-39 7717B (TWA 11B), member of the young stellar association TW Hya (~ 8 Myr). Only the rise phase (with a duration of ~ 35 ks) and possibly the flare peak were observed. We took advantage of the high count-rate of the X-ray source to carry out a detailed analysis of its spectrum during the whole exposure. After a careful analysis, we interpreted the rise phase as resulting from the ignition of a first group of loops (event A) which triggered a subsequent two-ribbon flare (event B). Event A was analyzed using a single-loop model, while a two-ribbon model was applied for event B. Loop semi-lengths of ~ 4 R* were obtained. Such large structures had been previously observed in very young stellar objects (~ 1 - 4 Myr). This is the first time that they have been inferred in a slightly more evolved star. The fluorescent iron emission line at 6.4 keV was detected during event B. Since TWA 11B seems to have no disk, the most plausible explanation found for its presence in the X-ray spectrum of this star is collisional - or photo- ionization. As far as we are concerned, this is only the third clear detection of Fe photospheric fluorescence in stars other than the Sun.Comment: Accepted for publication in ApJ. 15 pages, 9 figure

Superconducting qubit manipulated by fast pulses: experimental observation of distinct decoherence regimes

A particular superconducting quantum interference device (SQUID)qubit, indicated as double SQUID qubit, can be manipulated by rapidly modifying its potential with the application of fast flux pulses. In this system we observe coherent oscillations exhibiting non-exponential decay, indicating a non trivial decoherence mechanism. Moreover, by tuning the qubit in different conditions (different oscillation frequencies) by changing the pulse height, we observe a crossover between two distinct decoherence regimes and the existence of an "optimal" point where the qubit is only weakly sensitive to intrinsic noise. We find that this behaviour is in agreement with a model considering the decoherence caused essentially by low frequency noise contributions, and discuss the experimental results and possible issues.Comment: 16 pages, 9 figure

An Optimal Tunable Josephson Element for Quantum Computing

We introduce a three-junction SQUID that can be effectively used as an optimal tunable element in Josephson quantum computing applications. This device can replace the simple dc SQUID generally used as tunable element in this kind of applications, with a series of advantages for the coherence time and for the tolerance to small errors. We study the device both theoretically and experimentally at 4.2 K, obtaining a good agreement between the results.Comment: 3 pages, 4 figure

Nonlinear Localization in Metamaterials

Metamaterials, i.e., artificially structured ("synthetic") media comprising weakly coupled discrete elements, exhibit extraordinary properties and they hold a great promise for novel applications including super-resolution imaging, cloaking, hyperlensing, and optical transformation. Nonlinearity adds a new degree of freedom for metamaterial design that allows for tuneability and multistability, properties that may offer altogether new functionalities and electromagnetic characteristics. The combination of discreteness and nonlinearity may lead to intrinsic localization of the type of discrete breather in metallic, SQUID-based, and ${\cal PT}-$symmetric metamaterials. We review recent results demonstrating the generic appearance of breather excitations in these systems resulting from power-balance between intrinsic losses and input power, either by proper initialization or by purely dynamical procedures. Breather properties peculiar to each particular system are identified and discussed. Recent progress in the fabrication of low-loss, active and superconducting metamaterials, makes the experimental observation of breathers in principle possible with the proposed dynamical procedures.Comment: 19 pages, 14 figures, Invited (Review) Chapte

La completezza della documentazione sanitaria: ruolo dei Link Professional nel miglioramento continuo

INTRODUZIONE \u2013 premesse e scopo dello studio: La completezza della Cartella Clinica (CC) \ue8 un indicatore della qualit\ue0 delle cure erogate, per questo la valutazione regolare del contenuto rientra nelle attivit\ue0 di miglioramento continuo. Scopo di questo studio \ue8 valutare se il coinvolgimento e la formazione specifica di professionisti gi\ue0 impegnati nell\u2019attivit\ue0 assistenziale e clinica abbia un effetto sulla completezza della CC introdotta presso le due Strutture Operative Complesse (Medicina Fisica e Unit\ue0 Spinale, Medicina Fisica e Unit\ue0 delle Gravi Cerebro-lesioni acquisite) del Dipartimento Medicina Fisica e Riabilitazione (IMFR) di Udine. MATERIALI E METODI: Nel dicembre 2017 \ue8 stata adottata dall\u2019IMFR una nuova CC integrata multidisciplinare e ne \ue8 stato valutato l\u2019impatto in termini di completezza a gennaio 2018 (T0). Contestualmente sono stati formati sulla corretta compilazione della CC 17 link professional che, fungendo da raccordo tra i colleghi operatori e direzione ospedaliera, nelle settimane successive hanno promosso incontri periodici di formazione e approfondimento sul tema coinvolgendo tutto il personale sanitario. La completezza della CC \ue8 stata rivalutata a maggio 2018 (T1), a valle degli incontri formativi. Le misurazioni sono state effettuate mediante valutazione da parte dei link professional su 38 CC (20 a T0 ed 18 a T1) di pazienti in ricovero ordinario, utilizzando la medesima griglia composta da 10 sezioni, articolate in 59 voci. Per valutare l\u2019eventuale miglioramento \ue8 stata calcolata la completezza complessiva e la differenza tra T0 e T1 (\uf044T1-T0) in termini percentuali ed \ue8 stata effettuata una verifica del test d\u2019ipotesi con \uf0632. RISULTATI: La completezza complessiva della CC delle due strutture \ue8 aumentata significativamente (p<0,01), passando dal 62% (T0) all\u201980% (T1). A T1 \ue8 stata raggiunta, con un miglioramento significativo (p<0,01), una completezza pari al 100% nella sezione consensi (\uf044=29%), al 98% nella valutazione riabilitativa (\uf044=20%), al 92% nella lettera di dimissione (\uf044=29%), all\u201985% nella valutazione infermieristica (\uf044=13%), all\u201982% nel progetto riabilitativo individuale (\uf044=24%), al 74% nel piano integrato di cura (\uf044=15%) e al 77% nella grafica e scheda terapia (\uf044=34%). Un miglioramento, anche se non significativo, \ue8 stato registrato nelle rimanenti sezioni: valutazione medica (completezza: 82%, \uf044=6%), diario integrato (65%, \uf044=17%) e varie (64%, \uf044=8%). CONCLUSIONI: Il modello adottato si \ue8 dimostrato efficace nel supportare il processo di miglioramento della completezza della cartella clinica