Monte Carlo simulation of electric conductivity for pure and doping fullerene (C60)

In this paper, we have used Monte Carlo (MC) method to simulate and study the temperature and doping effects on the electric conductivity of fullerene (C60). The results show that the band gap has reduced by the doping and the charge carrier transport is facilitated from valence band to conduction band by the temperature where is touched a 300 K. In this case, the conductivity reached a value of $4\times {10}^{-7}\text{S}{\text{cm}}^{-1}$. The electric conductivity of C60 can increase by the triphenylmethane dye crystal violet (CV) alkali metal to reach $4\times {10}^{-3}\text{S}{\text{cm}}^{-1}$ at 303 K. Our results of MC simulation have a good agreement with those extracted from literature [10], [33].     

Resonance studies using the contour deformation method in the complex momentum plane

A contour deformation method (CDM) in the complex momentum plane has been successfully extended and implemented to probe resonances in atomic and molecular systems. Specifically, solution of the Schrödinger equation is performed in momentum space with momentum deformed on a contour in the complex plane. The bound, resonant, and complex continuum states could be directly revealed from the eigenvalues of the Schrödinger equation in the complex momentum plane. The calculations of shape resonances in electron scattering with Na⁺ in Debye plasmas (one channel), and in the charge transfer process ${\mathrm{H}}^{?}(1s^2)+\mathrm{Li}(1s^{2}2s)$ ($1^2{\Sigma }^{+}$) $\to \mathrm{H}(1s)+{\mathrm{Li}}^{?}(1s^{2}2s^2)$ ($2^2{\Sigma }^{+}$) (coupled channels) are given as illustrative examples. It is shown that calculated results from CDM agree very well with those extracted from the eigenphase sum of scattering theories. The effectiveness of CDM is also demonstrated by comparing its results with those obtained by the complex rotation scaling and exterior complex scaling methods. The convergence of CDM results can be obtained by increasing the momentum integration region and the number of integration points. The studied examples demonstrate that CDM could be a powerful tool for studies of resonances in complex atomic and molecular systems.     

Effect of bilayer repeats on magnetic properties of Au-buffered Co/Ni multilayers with perpendicular magnetic anisotropy

The effect of bilayer repeats (N) on the static and dynamic magnetic properties of Co/Ni multilayers was investigated. The effective perpendicular magnetic anisotropy constant of multilayers drops from $1.08\times {10}^6$ erg/cm³ to $0.78\times {10}^6$ erg/cm³ with N increasing from 5 to 11. For Co/Ni multilayers with $N\le 7$, sharp magnetization switching was observed. In contrast, Co/Ni multilayers with $N\ge 9$ have a long tail in the hysteresis loop. Ferromagnetic resonance measurements show that intrinsic Gilbert damping changes from 0.021 to 0.016 with increase in N and is inversely proportional to N. This study provides a deep understanding and effective control of magnetic properties of Co/Ni multilayers for spintronics devices.     

Influence of Ag thickness on the structural,optical, and electrical properties of the SnS/Ag/SnS trilayer films for solar cell application

We fabricated the SnS/Ag/SnS (SAS) trilayer thin films by a sputtering method at 200 $°C$. The structural, optical, and electrical properties of the films were studied by varying the Ag interlayer thickness from 9 to 27 nm. The EDS analysis revealed that all SAS trilayer films showed an increase in the atomic percentage of Ag from 1.87 to 6.18. The X-ray diffraction studies confirmed that SAS films with Ag-18 nm thickness showed a preferred (111) peak of the SnS with improved crystallinity. The optical absorption coefficient of the SAS films increased by a factor of 18 when compared to the SnS films without Ag. Also, the optical band gap decreased from 1.53 to 1.28 eV with Ag thickness. All SAS films exhibited the p-type conductivity with increased hole-concentration from 1.94 $\times$ ${10}^{14}$ to 4.15 $\times$${10}^{18}$cm⁻³ and also the mobility from 1.31 to 81.6 cm². V⁻¹s⁻¹.     

Levitation of a rapidly oscillating magnetic dipole above a metallic sheet

We show that such a magnetic dipole suspended at a height h above a conducting sheet experiences a lift force proportional to $1/h^2$. This represents an order of magnitude improvement over the $1/h^4$ lift obtained in the quasistatic limit.     

A Family-nonuniversal U(1)′ Model for Excited Beryllium Decays

Excited beryllium has been observed to decay into electron-positron pairs with a $6.8\sigma$ anomaly. The process is properly explained by a 17 MeV proto-phobic vector boson. In present work, we consider a family-nonuniversal $U{\left(1\right)}^{\prime }$ that is populated by a $U{\left(1\right)}^{\prime }$ gauge boson $Z^{\prime }$ and a scalar field $S,$ charged under $U{\left(1\right)}^{\prime }$ and singlet under the Standard Model (SM) gauge symmetry. The SM chiral fermion and scalar fields are charged under $U{\left(1\right)}^{\prime }$ and we provide them to satisfy the anomaly-free conditions. The Cabibbo-Kobayashi-Maskawa (CKM) matrix is reproduced correctly by higher-dimension Yukawa interactions facilitated by $S$. The vector and axial-vector current couplings of the $Z^{\prime }$ boson to the first generation of fermions do satisfy all the bounds from the various experimental data. The $Z^{\prime }$ boson can have kinetic mixing with the hypercharge gauge boson and $S$ can directly couple to the SM-like Higgs field. The kinetic mixing of $Z^{\prime }$ with the hypercharge gauge boson, as we show by a detailed analysis, generates the observed beryllium anomaly. We find that beryllium anomaly can be properly explained by a MeV-scale sector with a minimal new field content. The minimal model we construct forms a framework in which various anomalous SM decays can be discussed.     

Time-periodic quantum states of weakly interacting bosons in a harmonic trap

We consider quantum bosons with contact interactions at the Lowest Landau Level (LLL) of a two-dimensional isotropic harmonic trap. At linear order in the coupling parameter g, we construct a large, explicit family of quantum states with energies of the form $E_0+g{E}_1/4+O(g^2)$, where $E_0$ and $E_1$ are integers. Any superposition of these states evolves periodically with a period of $8\pi /g$ until, at much longer time scales of order $1/g^2$, corrections to the energies of order $g^2$ may become relevant. These quantum states provide a counterpart to the known time-periodic behaviors of the corresponding classical (mean field) theory.     

Equal heartbeat intervals and their effects on the nonlinearity of permutation-based time irreversibility in heart rate

The association of equal heartbeat intervals with cardiac conditions and the effect of the equality on permutation-based time irreversibility are investigated in this paper. We measure the distributions of equal heartbeat intervals under three conditions, namely congestive heart failure (CHF), healthy young and elderly, whose time irreversibility is detected by measuring the probabilistic difference between permutations instead of raw vectors. We demonstrate that heartbeats contain high rates of equal states, particularly the CHF with around 20% equalities, and the distributions of equal values discriminate the heartbeats at very short data length. The CHF have more equal values than the healthy young (p $<1.47?{10}^{?15}$) and elderly (p $<2.48?{10}^{?11}$), and the healthy young have less equalities than the elderly (p $<3.16?{10}^{?4}$). Time irreversibility considering equal values is promising to extract nonlinear behaviors of heartbeats, confirming the decreased nonlinear complexity of the diseased and aging heart rates, while that involving no equality leads to erroneous nonlinearity detection. In our contribution, we highlight the pathological or physiological information contained by the distribution of equal heartbeat intervals that might contribute to develop relevant biomarkers in the area of heart analysis, and demonstrate the effectiveness of equality-based time irreversibility in the nonlinearity detection of heartbeats.     

Highly sensitive selectively coated D-shape photonic crystal fibers for surface plasmon resonance sensing

We propose a design for a high sensitivity plasmon resonance (SPR) sensor based on photonic crystal fiber (PCF) and analyze the sensor using finite element software (FEM). By introducing a D-shape hole instead of a circular hole in the first ring of the photonic crystal fiber, which increases the coupling effect and proficient infiltration of the sensing, resulting in enhance the performance of the sensor due to the flat structure of the D-shape hole and the homogeneous metal coating facility. We study the influence of the parameters of the D-shape hole on the sensing performance and analyze the sensor performance based on the wavelength and amplitude sensitivity. The results show that the proposed sensor is capable of detecting analyte refractive index ranging from 1.30 to 1.42, and the maximum sensitivities of 14,600 nm/RIU and 1475 RIU^?1 can be achieved in this sensing range, respectively. The largest sensor resolutions for wavelength and amplitude sensing are $6.84\times {10}^{?6}$ and $6.78\times {10}^{?6}\text{ RIU}$, and the maximum figure of merits (FOM) of the proposed sensor being 618.     

Experimental determination of interfacial energy for solid Al in the Al-Sn-Mg eutectic system with Bridgman-type apparatus

The equilibrated grain boundary groove shape of solid Al in equilibrium with Al-Sn-Mg eutectic liquid was observed by using a Bridgman type directional solidification apparatus. The ratio of the thermal conductivity of the equilibrated liquid to the thermal conductivity of solid Al has been obtained as 0.91. In addition, the average Gibbs-Thomson coefficient, $\bar{\mathrm{\Gamma }}=(4.20\pm 0.35)\times {10}^{-8}\mathrm{Km}$, the solid-liquid interfacial energy, ${\sigma }_{SL}=180.68\pm 23.48\text{mJ}/{\text{m}}^2$ and the grain boundary energy, ${\sigma }_{GB}=309.30\pm 29.47\text{mJ}/{\text{m}}^2$, in the Al/Al-Sn-Mg system have been calculated from the measured grain boundary shapes.     

New findings for two new type sine hyperbolic potentials

We propose two new type sine hyperbolic potentials $V(x)=a^2{\sinh }^2?(x)?k{\tanh }^2?(x)$ and $V(x)=c^2{\sinh }^4?(x)?k{\tanh }^2?(x)$. They may become single- or double-well potentials depending on the potential parameters $a,c$ and k. We find that its exact solutions can be written as the confluent Heun functions $H_c(\alpha ,\beta ,\gamma ,\delta ,\eta ;z)$, in which the energy level E is involved inside the parameter η. The properties of the wave functions, which is strongly relevant for the potential parameters $a,c$ and k, are illustrated.