The generalized Fresnel–Hadamard complementary transformation for asymmetric beamsplitter

Based on the newly developed parameterized coherent-entangled state representation we propose so-called the generalized Fresnel–Hadamard complementary transformation for asymmetric beamsplitter, which is unitary. The new unitary operator plays the role of both Fresnel transformation for a₁ sin θ ? a₂ cos θ and Hadamard transformation for a₁ cos θ + a₂ sin θ, respectively. Physically, a₁ sin θ ? a₂ cos θ and a₁ cos θ + a₂ sin θ could be a asymmetric beamsplitter’s two output fields. We show that the two transformations are concisely expressed in the parameterized coherent-entangled state representation as a projective operator in integration form.     

Effect of polarization properties on Doppler velocimetry with Vertical-Cavity Surface-Emitting lasers

This paper presents experimental results and numerical analysis of polarization properties of Vertical-Cavity Surface-Emitting lasers used for Doppler velocimetry. A good match is found between the numerical results and the experimental results. It include that generating symmetric self-mixing waveforms of the VCSELs must be operated in the bistable region and the frequency difference between the two linear polarization modes must be equal to one of several certain values. We also show that we can select VCSELs that have a frequency difference between the linear polarization modes that is a multiple of ±3 GHz in order to obtain an asymmetric self-mixing waveform.     

Temperature independent leakage current in Au/TbMnO3/Y Ba2Cu3O7−x capacitors

Au/TbMnO₃/Y Ba₂Cu₃O_7?x capacitors were fabricated on LaAlO₃ substrates and electrical characteristics were studied in the temperature range from 300 to 25 K. When temperature is higher than 225 K, Ohmic conduction is observed in the capacitors. Non-linear current–voltage characteristics are exhibited at low temperatures. Moreover, temperature-independent leakage currents are found at temperatures lower than 150 K. These electrical characteristics can be explained in terms of conduction transition originated from a thermal activation between 225 and 150 K, and the temperature-independent leakage currents are governed by the Poole–Frenkel emission and minor trap ionization energies.     

Dynamics of quantum discord in the purification process

We investigate the dynamics of quantum discord during the purification process. In the case of Werner states, it is shown that quantum discord is increased after a round of purification protocol. Furthermore, quantum mutual information and classical correlation is also increased during this process. We also give an analytic expression for a class of higher dimensional states which have additive quantum discord.     

Loss compensated negative index material at optical wavelengths

We present a computational approach, allowing for a self-consistent treatment of three-dimensional (3D) fishnet metamaterial operating at 710 nm wavelength coupled to a gain material incorporated into the nanostructure. We show numerically that loss-free negative index material is achievable by incorporating gain material inside the fishnet structure. The effective gain coefficient of the combined fishnet-gain system is much larger than its bulk counterpart and the figure-of-merit (FOM = | Re(n)/Im(n) |) increases dramatically with gain. Transmission, reflection, and absorption data, as well as the retrieved effective parameters, are presented for the fishnet structure with and without gain.     

Temperature-insensitive Mach-Zehnder interferometric strain sensor based on concatenating two waist-enlarged fiber tapers

A novel temperature-insensitive strain sensor,based on an in-line Mach-Zehnder interferometer,is fabricated by concatenating two waist-enlarged fiber tapers separated by a short piece of photonic crystal fiber. The interference spectrum of the proposed sensor is analyzed in detail.Experimental results demonstrate that this sensor has a strain sensitivity of.3.02 pm/μεand maintains the temperature insensitivity feature. The proposed sensor has great potential in diverse sensing applications due to its advantages,such as its compact size,low cost,and simple fabrication process.     

Exponential inequalities and inverse moment for NOD sequence

Some exponential inequalities for a negatively orthant dependent sequence are obtained. By using the exponential inequalities, we study the asymptotic approximation of inverse moment for negatively orthant dependent random variables, which generalizes and improves the corresponding results of Kaluszka and Okolewski [Kaluszka, M., Okolewski, A., 2004. On Fatou-type lemma for monotone moments of weakly convergent random variables. Statist. Probab. Lett. 66, 45–50], Hu et al. [Hu, S.H., Chen, G.J., Wang, X.J., Chen, E.B., 2007. On inverse moments of nonnegative weakly convergent random variables. Acta Math. Appl. Sin. 30, 361–367(in Chinese)] and Wu et al. [Wu, T.J., Shi, X.P., Miao, B.Q., 2009. Asymptotic approximation of inverse moments of nonnegative random variables. Statist. Probab. Lett. 79, 1366–1371].     

Toeplitz-Bezout矩阵的若干性质

从定义出发,利用矩阵生成函数的方法来研究Toeplitz-Bezout若干基本性质,同时利用极限的思想将其对角约化.     

关于N-弱鞅和弱鞅不等式的一个注记

$N$-弱鞅($N$-demimartingales)是由Christofides引进的.Christofides指出均值为零的负相协(negatively associated)随机变量序列的部分和序列是$N$-弱鞅. 然而, 相关文献中引理2.1的证明有错误, 这就影响了其文后的结果引理2.2、定理2.1等. 在这篇注记中,修正了相关文献中的引理2.1, 作为应用, 推广了鞅和下鞅的一些结果.     

Condensation of analyte vapor species in graphite furnace atomic absorption spectrometry

A shadow spectral digital imaging technique (SSDI) with charge coupled device (CCD) camera detection was used to investigate the spatial and temporal distribution of condensation clouds of analyte species generated in a graphite furnace during the atomization of 5–40-μg masses of metals. Complex, non-uniform structures of aerosol species located away from both the graphite tube axis and walls are prevalent. Species giving rise to observed signals are likely clusters of metals in the case of Ag, Au and Pd, and oxide aerosols for elements such as Al, Ca and Mg. Source scatter often arises during the atomization of relatively large masses of analytes (or during the atomization of real samples containing high concentrations of concomitant matrix species) in the graphite furnace due to such aerosol formation. The SSDI technique is an extremely useful aid to the elucidation of this phenomenon and imaging at several wavelengths using both line and continuum sources in combination with (thermal, incandescent) emission from these structures permits a more complete picture to be developed.