159,808 research outputs found

    Spin-dependent Fano resonance induced by conducting chiral helimagnet contained in a quasi-one-dimensional electron waveguide

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    Fano resonance appears for conduction through an electron waveguide containing donor impurities. In this work, we consider the thin-film conducting chiral helimagnet (CCH) as the donor impurity in a one-dimensional waveguide model. Due to the spin spiral coupling, interference between the direct and intersubband transmission channels gives rise to spin-dependent Fano resonance effect. The spin-dependent Fano resonance is sensitively dependent on the helicity of the spiral. By tuning the CCH potential well depth and the incident energy, this provides a potential way to detect the spin structure in the CCH.Comment: 14 pages, 6 figure

    The stochastic reflection problem on an infinite dimensional convex set and BV functions in a Gelfand triple

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    In this paper, we introduce a definition of BV functions in a Gelfand triple which is an extension of the definition of BV functions in [2] by using Dirichlet form theory. By this definition, we can consider the stochastic reflection problem associated with a self-adjoint operator AA and a cylindrical Wiener process on a convex set Γ\Gamma in a Hilbert space HH. We prove the existence and uniqueness of a strong solution of this problem when Γ\Gamma is a regular convex set. The result is also extended to the non-symmetric case. Finally, we extend our results to the case when Γ=Kα\Gamma=K_\alpha, where Kα=f∈L2(0,1)∣f≥−α,α≥0K_\alpha={f\in L^2 (0,1)|f\geq -\alpha},\alpha\geq0

    Systematic analysis of hadron spectra in p+p collisions using Tsallis distribution

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    Using the experimental data from the STAR, PHENIX, ALICE and CMS programs on the rapidity and energy dependence of the pTp_T spectra in p+p collisions, we show that a universal distribution exists. The energy dependence of temperature TT and parameter nn of the Tsallis distribution are also discussed in detail. A cascade particle production mechanism in p+p collisions is proposed.Comment: 13 pages, 8 figure

    On the spectral distribution of kernel matrices related to\ud radial basis functions

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    This paper focuses on the spectral distribution of kernel matrices related to radial basis functions. The asymptotic behaviour of eigenvalues of kernel matrices related to radial basis functions with different smoothness are studied. These results are obtained by estimated the coefficients of an orthogonal expansion of the underlying kernel function. Beside many other results, we prove that there are exactly (k+d−1/d-1) eigenvalues in the same order for analytic separable kernel functions like the Gaussian in Rd. This gives theoretical support for how to choose the diagonal scaling matrix in the RBF-QR method (Fornberg et al, SIAM J. Sci. Comput. (33), 2011) which can stably compute Gaussian radial basis function interpolants

    Quench Dynamics of Entanglement in an Opened Anisotropic Spin-1/2 Heisenberg Chain

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    The quantum entanglement dynamics of a one-dimensional spin-1/2 anisotropic XXZ model is studied using the method of the adaptive time-dependent density-matrix renormalization-group when two cases of quenches are performed in the system. An anisotropic interaction quench and the maximum number of domain walls of staggered magnetization quench are considered. The dynamics of pairwise entanglement between the nearest two qubits in the spin chain is investigated. The entanglement of the two-spin qubits can be created and oscillates in both cases of the quench. The anisotropic interaction has a strong influence on the oscillation frequency of entanglement.Comment: 13 pages, 4 figure
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