336 research outputs found

    Quantum transport thermometry for electrons in graphene

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    We propose a method of measuring the electron temperature TeT_e in mesoscopic conductors and demonstrate experimentally its applicability to micron-size graphene devices in the linear-response regime (Te≈TT_e\approx T, the bath temperature). The method can be {especially useful} in case of overheating, Te>TT_e>T. It is based on analysis of the correlation function of mesoscopic conductance fluctuations. Although the fluctuation amplitude strongly depends on the details of electron scattering in graphene, we show that TeT_e extracted from the correlation function is insensitive to these details.Comment: 4 pages, 4 figures; final version, as publishe

    Influence of trigonal warping on interference effects in bilayer graphene

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    Bilayer graphene (two coupled graphitic monolayers arranged according to Bernal stacking) is a two-dimensional gapless semiconductor with a peculiar electronic spectrum different from the Dirac spectrum in the monolayer material. In particular, the electronic Fermi line in each of its valleys has a strong p -> -p asymmetry due to trigonal warping, which suppresses the weak localization effect. We show that weak localization in bilayer graphene may be present only in devices with pronounced intervalley scattering, and we evaluate the corresponding magnetoresistance

    On Multiparticle Entanglement via Resonant Interaction between Light and atomic Ensembles

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    Multiparticle entangled states generated via interaction between narrow-band light and an ensemble of identical two-level atoms are considered. Depending on the initial photon statistics, correlation between atoms and photons can give rise to entangled states of these systems. It is found that the state of any pair of atoms interacting with weak single-mode squeezed light is inseparable and robust against decay. Optical schemes for preparing entangled states of atomic ensembles by projective measurement are described.Comment: 11 pages, 1 figure, revtex

    Descent Relations and Oscillator Level Truncation Method

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    We reexamine the oscillator level truncation method in the bosonic String Field Theory (SFT) by calculation the descent relation =Z_3<V_2|. For the ghost sector we use the fermionic vertices in the standard oscillator basis. We propose two new schemes for calculations. In the first one we assume that the insertion satisfies the overlap equation for the vertices and in the second one we use the direct calculations. In both schemes we get the correct structures of the exponent and pre-exponent of the vertex <V_2|, but we find out different normalization factors Z_3.Comment: 21 pages, 10 figures, Late

    Coexistence of electron and hole transport in graphene

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    When sweeping the carrier concentration in monolayer graphene through the charge neutrality point, the experimentally measured Hall resistivity shows a smooth zero crossing. Using a two- component model of coexisting electrons and holes around the charge neutrality point, we unambiguously show that both types of carriers are simultaneously present. For high magnetic fields up to 30 T the electron and hole concentrations at the charge neutrality point increase with the degeneracy of the zero-energy Landau level which implies a quantum Hall metal state at \nu=0 made up by both electrons and holes.Comment: 5 pages, 6 figure

    Descent Relations in Cubic Superstring Field Theory

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    The descent relations between string field theory (SFT) vertices are characteristic relations of the operator formulation of SFT and they provide self-consistency of this theory. The descent relations and in the NS fermionic string field theory in the kappa and discrete bases are established. Different regularizations and schemes of calculations are considered and relations between them are discussed.Comment: Replaced to JHEP styl

    Enumeration of self-avoiding walks on the square lattice

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    We describe a new algorithm for the enumeration of self-avoiding walks on the square lattice. Using up to 128 processors on a HP Alpha server cluster we have enumerated the number of self-avoiding walks on the square lattice to length 71. Series for the metric properties of mean-square end-to-end distance, mean-square radius of gyration and mean-square distance of monomers from the end points have been derived to length 59. Analysis of the resulting series yields accurate estimates of the critical exponents γ\gamma and ν\nu confirming predictions of their exact values. Likewise we obtain accurate amplitude estimates yielding precise values for certain universal amplitude combinations. Finally we report on an analysis giving compelling evidence that the leading non-analytic correction-to-scaling exponent Δ1=3/2\Delta_1=3/2.Comment: 24 pages, 6 figure

    Microbial landscape patients with advanced sterile pancreatic necrosis in the dynamics of complex treatment

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    Method of gas chromatography - mass spectrometry was used for the study of microbial landscape of patients with pancreatonecrosis. It was found that the provision of sterile necrotic destruction dysbiosis occurs that requires correction during the treatment. Unlike conventional methods of diagnosis of infection pancreatogenic gas chromatography - mass spectrometry allows to express mode (3 hours) monitored landscape microbial degradation pancreatogenic patients. In patients with necrotizing pancreatitis concentration of organisms was determined in serum on admission, on day 5, day 10, day 15, day 20 of treatment. Data on the composition of microorganisms, participants of widespread sterile necrotic destruction when assessing the overall microecological status, obtained for each patient allow to get a qualitatively new comprehensive information to make adequate antibiotic therapy and complex treatment that significantly broadens the etiology of this disease
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