46,430 research outputs found

    Microscopic origin of the next generation fractional quantum Hall effect

    Full text link
    Most of the fractions observed to date belong to the sequences ν=n/(2pn±1)\nu=n/(2pn\pm 1) and ν=1n/(2pn±1)\nu=1-n/(2pn\pm 1), nn and pp integers, understood as the familiar {\em integral} quantum Hall effect of composite fermions. These sequences fail to accommodate, however, many fractions such as ν=4/11\nu=4/11 and 5/13, discovered recently in ultra-high mobility samples at very low temperatures. We show that these "next generation" fractional quantum Hall states are accurately described as the {\em fractional} quantum Hall effect of composite fermions

    The induced representations of Brauer algebra and the Clebsch-Gordan coefficients of SO(n)

    Get PDF
    Induced representations of Brauer algebra Df(n)D_{f}(n) from Sf1×Sf2S_{f_{1}}\times S_{f_{2}} with f1+f2=ff_{1}+f_{2}=f are discussed. The induction coefficients (IDCs) or the outer-product reduction coefficients (ORCs) of Sf1×Sf2Df(n)S_{f_{1}}\times S_{f_{2}}\uparrow D_{f}(n) with f4f\leq 4 up to a normalization factor are derived by using the linear equation method. Weyl tableaus for the corresponding Gel'fand basis of SO(n) are defined. The assimilation method for obtaining CG coefficients of SO(n) in the Gel'fand basis for no modification rule involved couplings from IDCs of Brauer algebra are proposed. Some isoscalar factors of SO(n)SO(n1)SO(n)\supset SO(n-1) for the resulting irrep [λ1, λ2, λ3, λ4,0˙][\lambda_{1},~\lambda_{2},~ \lambda_{3},~\lambda_{4},\dot{0}] with $\sum\limits_{i=1}^{4}\lambda_{i}\leq .Comment: 48 pages latex, submitted to Journal of Phys.

    Whole tumor RNA-sequencing and deconvolution reveal a clinically-prognostic PTEN/PI3K-regulated glioma transcriptional signature

    Get PDF
    The concept that solid tumors are maintained by a productive interplay between neoplastic and non-neoplastic elements has gained traction with the demonstration that stromal fibroblasts and immune system cells dictate cancer development and progression. While less studied, brain tumor (glioma) biology is likewise influenced by non-neoplastic immune system cells (macrophages and microglia) which interact with neoplastic glioma cells to create a unique physiological state (glioma ecosystem) distinct from that found in the normal tissue. To explore this neoplastic ground state, we leveraged several preclinical mouse models of neurofibromatosis type 1 (NF1) optic glioma, a low-grade astrocytoma whose formation and maintenance requires productive interactions between non-neoplastic and neoplastic cells, and employed whole tumor RNA-sequencing and mathematical deconvolution strategies to characterize this low-grade glioma ecosystem as an aggregate of cellular and acellular elements. Using this approach, we demonstrate that optic gliomas generated by altering the germlin

    A New Young Diagrammatic Method For Kronecker Products of O(n) and Sp(2m)

    Get PDF
    A new simple Young diagrammatic method for Kronecker products of O(n) and Sp(2m) is proposed based on representation theory of Brauer algebras. A general procedure for the decomposition of tensor products of representations for O(n) and Sp(2m) is outlined, which is similar to that for U(n) known as the Littlewood rules together with trace contractions from a Brauer algebra and some modification rules given by King.Comment: Latex, 11 pages, no figure

    Periodic Coherence Peak Height Modulations in Superconducting BSCCO

    Full text link
    In this paper we analyze, using scanning tunneling spectroscopy (STS), the local density of electronic states (LDOS) in nearly optimally doped BSCCO in zero field. We see both dispersive and non-dispersive spatial LDOS modulations as a function of energy in our samples. Moreover, a spatial map of the superconducting coherence peak heights shows the same structure as the low energy LDOS. This suggests that these non-dispersive LDOS modulations originate from an underlying charge-density modulation which interacts with superconductivity.Comment: 8 pages, 5 figures with 15 total eps file

    Swift UVOT Grism Observations of Nearby Type Ia Supernovae - I. Observations and Data Reduction

    Get PDF
    Ultraviolet (UV) observations of Type Ia supernovae (SNe Ia) are useful tools for understanding progenitor systems and explosion physics. In particular, UV spectra of SNe Ia, which probe the outermost layers, are strongly affected by the progenitor metallicity. In this work, we present 120 Neil Gehrels Swift Observatory UV spectra of 39 nearby SNe Ia. This sample is the largest UV (lambda < 2900 A) spectroscopic sample of SNe Ia to date, doubling the number of UV spectra and tripling the number of SNe with UV spectra. The sample spans nearly the full range of SN Ia light-curve shapes (delta m(B) ~ 0.6-1.8 mag). The fast turnaround of Swift allows us to obtain UV spectra at very early times, with 13 out of 39 SNe having their first spectra observed >~ 1 week before peak brightness and the earliest epoch being 16.5 days before peak brightness. The slitless design of the Swift UV grism complicates the data reduction, which requires separating SN light from underlying host-galaxy light and occasional overlapping stellar light. We present a new data-reduction procedure to mitigate these issues, producing spectra that are significantly improved over those of standard methods. For a subset of the spectra we have nearly simultaneous Hubble Space Telescope UV spectra; the Swift spectra are consistent with these comparison data.Comment: Accepted for publication in MNRA

    Incidence of fires and related injuries after giving out free smoke alarms: cluster randomised controlled trial

    Get PDF
    Objective To measure the effect of giving out free smoke alarms on rates of fires and rates of fire related injury in a deprived multiethnic urban population. Design Cluster randomised controlled trial. Setting Forty electoral wards in two boroughs of inner London, United Kingdom. Participants Primarily households including elderly people or children and households that are in housing rented from the borough council. Intervention 20 050 smoke alarms, fittings, and educational brochures distributed free and installed on request. Main outcome measures Rates of fires and related injuries during two years after the distribution; alarm ownership, installation, and function. Results Giving out free smoke alarms did not reduce injuries related to fire (rate ratio 1.3; 95% confidence interval 0.9 to 1.9), admissions to hospital and deaths (1.3; 0.7 to 2.3), or fires attended by the fire brigade (1.1; 0.96 to 1.3). Similar proportions of intervention and control households had installed alarms (36/119 (30%) v 35/109 (32%); odds ratio 0.9; 95% confidence interval 0.5 to 1.7) and working alarms (19/118 (16%) v 18/108 (17%); 0.9; 0.4 to 1.8). Conclusions Giving out free smoke alarms in a deprived, multiethnic, urban community did not reduce injuries related to fire, mostly because few alarms had been installed or were maintained

    WxN1–x alloys as diffusion barriers between Al and Si

    Get PDF
    Reactively sputtered tungsten nitride (WxN1–x) layers are investigated as diffusion barriers between Al overlayers and Si shallow n + -p junctions. Both amorphous W80 N20 and polycrystalline W60 N40 films were found to be very effective in preserving the integrity of the n + -p diodes for 30-min vacuum annealing up to 575 °C. Diode failure at higher temperatures is caused by localized penetration of Al into through the WxN1–x barriers. The effectiveness of the barrier decreases for polycrystalline W90 N10 and is worse for pure W
    corecore