Green's function and stability of a linear partial difference scheme

AbstractThis paper is concerned with a linear partial difference equation which arises from discretizing a heat and a first order wave equations. A Green's function for this equation is derived. Various representation theorems, monotonicity, and oscillatory properties of the Green's functions are obtained. Then by means of the representation theorems, we derive several stability criteria for arbitrary solutions of this equation

Ab initio study of the giant ferroelectric distortion and pressure induced spin-state transition in BiCoO3

Using configuration-state-constrained electronic structure calculations based on the generalized gradient approximation plus Hubbard U method, we sought the origin of the giant tetragonal ferroelectric distortion in the ambient phase of the potentially multiferroic material BiCoO3 and identified the nature of the pressure induced spin-state transition. Our results show that a strong Bi-O covalency drives the giant ferroelectric distortion, which is further stabilized by an xy-type orbital ordering of the high-spin (HS) Co3+ ions. For the orthorhombic phase under 5.8 GPa, we find that a mixed HS and low-spin (LS) state is more stable than both LS and intermediate-spin (IS) states, and that the former well accounts for the available experimental results. Thus, we identify that the pressure induced spin-state transition is via a mixed HS+LS state, and we predict that the HS-to-LS transition would be complete upon a large volume decrease of about 20%.Comment: 6 pages, 6 figures, 2 table

High visibility on-chip quantum interference of single surface plasmons

Quantum photonic integrated circuits (QPICs) based on dielectric waveguides have been widely used in linear optical quantum computation. Recently, surface plasmons have been introduced to this application because they can confine and manipulate light beyond the diffraction limit. In this study, the on-chip quantum interference of two single surface plasmons was achieved using dielectric-loaded surface-plasmon-polariton waveguides. The high visibility (greater than 90%) proves the bosonic nature of single plasmons and emphasizes the feasibility of achieving basic quantum logic gates for linear optical quantum computation. The effect of intrinsic losses in plasmonic waveguides with regard to quantum information processing is also discussed. Although the influence of this effect was negligible in the current experiment, our studies reveal that such losses can dramatically reduce quantum interference visibility in certain cases; thus, quantum coherence must be carefully considered when designing QPIC devices.Comment: 6 pages, 4 figure

A new modified Newton iteration for computing nonnegative Z-eigenpairs of nonnegative tensors

We propose a new modification of Newton iteration for finding some nonnegative Z-eigenpairs of a nonnegative tensor. The method has local quadratic convergence to a nonnegative eigenpair of a nonnegative tensor, under the usual assumption guaranteeing the local quadratic convergence of the original Newton iteration

Emergence Profile Index Implant Surgical Guide

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141934/1/cap0030.pd

Precise determination of the pole position of the exotic Zc(3900)Z_c(3900)

We perform a unified description of the experimental data of the $\pi^+\pi^-$ and $J/\psi\pi^\pm$ invariant mass spectra for $e^+e^- \rightarrow J/\psi \pi^+\pi^-$ and the $D^0 D^{\ast-}$ mass spectrum for $e^+e^- \rightarrow D^0 D^{\ast-} \pi^+$ at $e^+e^-$ center-of-mass energies 4.23 and 4.26 GeV. The analysis takes into account open-charm meson loops that contain triangle singularities, the $J/\psi\pi$-$D\bar D^*$ coupled-channel interaction respecting unitarity, and the strong $\pi\pi$-$K\bar K$ final state interaction using dispersion relations. The analysis leads to a precise determination of the $Z_c(3900)$ pole with the pole mass and width $(3880.5 \pm 2.6)$ MeV and $(25.5 \pm 2.5)$ MeV, respectively, and hints at that the $D\bar D^*$ molecular and non-molecular components are of similar importance in the $Z_c(3900)$ formation.Comment: 15 pages, 4 figure