129 research outputs found

    Emergence of Quintet Superfluidity in the Chain of Partially Polarized Spin-3/2 Ultracold Atom

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    The system of ultracold atoms with hyperfine spin F=3/2F=3/2 might be unstable against the formation of quintet pairs if the interaction is attractive in the quintet channel. We have investigated the behavior of correlation functions in a model including only s-wave interactions at quarter filling by large-scale density-matrix renormalization-group simulations. We show that the correlations of quintet pairs become quasi-long-ranged, when the system is partially polarized, leading to the emergence of various mixed superfluid phases in which BCS-like pairs carrying different magnetic moment coexist.Comment: 4 pages, 4 figures; significantly rewritten compared to the first versio

    Charged particle display

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    An optical shutter based on charged particles is presented. The output light intensity of the proposed device has an intrinsic dependence on the interparticle spacing between charged particles, which can be controlled by varying voltages applied to the control electrodes. The interparticle spacing between charged particles can be varied continuously and this opens up the possibility of particle based displays with continuous grayscale.Comment: typographic errors corrected in Eqs (37) and (39); published in Journal of Applied Physics; doi:10.1063/1.317648

    Insulating charge density wave for a half-filled SU(N) Hubbard model with an attractive on-site interaction in one dimension

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    We study a one-dimensional SU(N) Hubbard model with an attractive on-site interaction and N>2N>2 at half-filling on the bipartite lattice using density-matrix renormalization-group method and a perturbation theory. We find that the ground state of the SU(N) Hubbard model is a charge density wave state with two-fold degeneracy. All the excitations are found to be gapful, resulting in an insulating ground state, on contrary to that in the SU(2) case. Moreover, the charge gap is equal to the Cooperon gap, which behaves as 2Nt2/(N1)U-2Nt^2/(N-1)U in the strong coupling regime. However, the spin gap Δs\Delta_{s} and the quasiparticle gap Δ1\Delta_{1} as well open exponentially in the weak coupling region, while in the strong coupling region, they linearly depend on UU such that ΔsU(N1)\Delta_{s}\sim -U(N-1) and Δ1U(N1)/2\Delta_{1}\sim -U(N-1)/2.Comment: 7 pages, 7 figure

    Properties of excitations in systems with a spinor Bose-Einstein condensate

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    General theory in case of homogenous Bose-Einstein condensed systems with spinor condensate is presented for the correlation functions of density and spin fluctuations and for the one-particle propagators as well. The random phase approximation is investigated and the damping of the modes is given in the intermediate temperature region. It is shown that the collective and the one-particle excitation spectra do not coincide fully.Comment: 5 pages, 1 figur

    Halláscsökkenést okozó etiológiai tényezők cochleáris implantáción átesett gyerekeknél

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    Absztrakt: Bevezetés: Veleszületett halláscsökkenés 1000 újszülöttből 1–3 esetben fordul elő. A gyermekkori súlyos fokú percepciós halláscsökkenés hátterében számos ok szerepelhet. Az esetek döntő százalékában genetikai eredet valószínűsíthető, de emellett lehet infekció, fejlődési rendellenesség és egyéb szerzett megbetegedések is. Célkitűzés: Célunk volt a Semmelweis Egyetem Fül-, Orr-, Gégészeti és Fej-, Nyaksebészeti Klinikáján a 18 év alatti, cochlearis implantáción átesett betegek között az etiológiai tényezők előfordulási arányának felmérése. Módszer és eredmények: A halláscsökkenés okát betegeink 62,9%-ában meg tudtuk határozni. A leggyakoribb etiológia a gap junction protein β-2 gén c.35delG patogén mutációja, mely a vizsgált populációban 38,8%-os allélfrekvenciát mutatott. Emellett az infektív eredet (10,1%), a meningitishez, illetve a cytomegalovirusfertőzéshez társuló halláscsökkenés fordult elő nagyobb százalékban. Betegeink 79,7%-a részesült a beszédfejlődés lezáródását megelőzően műtéti rehabilitációban, a veleszületett halláscsökkent gyermekek 11,2%-a azonban továbbra is későn diagnosztizált eset volt. Következtetés: Eredményeink alapján elmondható, hogy a gyermekkori súlyos fokú halláscsökkenés esetén fontos a genetikai eredet tisztázása. Az időben megkezdett rehabilitáció a gyermek egész életére hatással van, késői implantáció esetén a gyermek beszédfejlődése jelentősen elmarad. A késői implantációk magas aránya a 2015-ben bevezetett új újszülöttkori hallásszűrés-protokollal, valamint az orvoskollégák megfelelő tájékoztatásával és a betegeknek a megfelelő centrumba történő irányításával várhatóan csökkenthető. Orv Hetil. 2019; 160(21): 822–828. | Abstract: Introduction: Congenital sensorineural hearing loss is one of the most common sensory defects affecting 1–3 children per 1000 newborns. There are a lot of causes which result in congenital hearing loss, the most common is the genetic origin, but infection, cochlear malformation or other acquired causes can be reasons as well. Aim: The aim of this study was to establish the etiological factors of congenital profound sensorineural hearing loss in children who underwent cochlear implantation. Results: Our results show that the origin of the hearing loss was discovered in 62.9% of our patients. The most common etiological factor was the c.35delG mutation of the gap junction protein β-2 gene, the allele frequency was 38.7% in our cohort. Infection constituted to 10.1%, and meningitis and cytomegalovirus infection were the second most common cause. 79.9% of our patients received sufficient hearing rehabilitation before the end of the speech development’s period (6 years old), but 11.2% of our cases were still diagnosed late. Conclusions: Based on our data we can state that genetic evaluation is crucial in the diagnostic process of congenital profound sensorineural hearing loss. Sufficient hearing rehabilitation affects the whole life of the child, and by late cochlear implantation the speech development falls behind. We can decrease the ratio of the late implantation with the new protocol of newborn hearing screening, and with sufficient information provided to the colleagues, so the children may be referred to the proper center for rehabilitation without delay. Orv Hetil. 2019; 160(21): 822–828
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