Quantum transport properties of ultrathin silver nanowires

The quantum transport properties of the ultrathin silver nanowires are investigated. For a perfect crystalline nanowire with four atoms per unit cell, three conduction channels are found, corresponding to three $s$ bands crossing the Fermi level. One conductance channel is disrupted by a single-atom defect, either adding or removing one atom. Quantum interference effect leads to oscillation of conductance versus the inter-defect distance. In the presence of multiple-atom defect, one conduction channel remains robust at Fermi level regardless the details of defect configuration. The histogram of conductance calculated for a finite nanowire (seven atoms per cross section) with a large number of random defect configurations agrees well with recent experiment.Comment: 4 pages, 6 figure

Production of true para-muonium in linearly polarized photon fusions

True muonium (TM) -- the bound state of $\mu^+\mu^-$ -- has not been discovered yet. It was demonstrated that searching for TM via $\gamma\gamma$ fusions in heavy ion collisions is feasible due to the enhancement of the atom number. We study the production of the true para-muonium (pTM) in the collisions of linearly polarized photons in the experiments of heavy-ion collisions, calculate the production rate as well as the transverse spectrum of pTM, and explore the discovery potential in nuclear experiments. Our results show that there is a significant correlation between the linearly polarized photon distribution and the transverse momentum distribution of pTM. The optimal kinematic region of the generated pTM is identified, which can provide a theoretical guide to the detection of pTM in experiments.Comment: 7 pages, 10 figures, 1 table. Accepted for publication in Physical Review

Calibrating the effective magnitudes of type Ia supernovae with a model-independent method

This research explores the correlation between the absolute magnitude and the redshift of Type Ia supernovae (SNe Ia) with a model-independent approach. The Pantheon sample of SNe Ia and strong gravitational lensing systems (SGLS) are used. With the cosmic distance-duality relation (CDDR), the evolution parameter of the magnitude, the light curve parameters of SNe Ia, and the parameters of the SGLS geometric model are constrained simultaneously. Considering the consistency of the redshifts, we selected a subsample of SNe Ia in which the redshift of each SNe Ia is close to the corresponding redshift of the SGLS sample. Two parametric models are used to describe this evolution, which can be written as $\delta_M=\varepsilon z$ and $\delta_M=\varepsilon\log(1+z)$, respectively. Our analysis reveals that $\varepsilon=-0.036^{+0.357}_{-0.339}$ in the first parametric model and $\varepsilon=-0.014^{+0.588}_{-0.630}$ in the second model, indicating that no significant evolution ($\varepsilon=0$) is supported at the 1$\sigma$ confidence level in this study. These results represent a significant advancement in our understanding of the intrinsic properties of SNe Ia and provide important constraints for future SNe Ia study.Comment: 8 pages, 2 figures, Accepted by Physical Review

The upper and lower solution method for nonlinear third-order three-point boundary value problem

This paper is concerned with the following nonlinear third-order three-point boundary value problem \left\{ \begin{array}{l} u^{\prime \prime \prime }(t)+f\left( t,u\left( t\right) ,u^{\prime}\left(t\right) \right) =0,\, t\in \left[ 0,1\right], \\ u\left( 0\right) =u^{\prime }\left( 0\right) =0,\, u^{\prime}\left( 1\right) =\alpha u^{\prime }\left( \eta \right),\label{1.1} \end{array} \right. where $0<\eta <1$ and $0\leq \alpha <1.$ A new maximum principle is established and some existence criteria are obtained for the above problem by using the upper and lower solution method