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The closed-form analytical expressions for the off-shell solutions for Hulthén-distorted Yamaguchi potential are derived to deal with the charged hadron systems. To construct these solutions, the particular integrals of the non-homogeneous Schrödinger equations are utilised in conjunction with the interacting Green’s functions. The Jost functions thus obtained, both on- and off-shell, are exploited to find the half-off-shell T-matrix. The off-shell Jost function exists but off-shell Jost solution for the said potential has not yet been discussed in the literature. The merits of the T-matrix are examined through some model calculations. Exploiting the expressions for on- and half-shell transition matrices, the s-wave elastic and inelastic scattering cross-sections are also estimated. Our results for the proton–proton and proton–oxygen systems are in close agreement with other calculations. [ABSTRACT FROM AUTHOR]

In this work, exact analytical expressions for regular solution and on-shell Jost function are calculated for nuclear Hulthén plus atomic Hulthén potential by imposing the same range approximation to both nuclear and atomic potentials. In this context, the regular solution is utilised to find expressions for the off-shell Jost function and half-shell T-matrix. The half-off-shell T-matrix and the elastic scattering phase shifts for the nucleon–nucleon and nucleus–nucleus systems are computed. Our results are found to be in good agreement with the standard data. [ABSTRACT FROM AUTHOR]

New analytical expressions for the off-shell wave functions and T-matrix with the Manning–Rosen potential are constructed in terms of generalised hypergeometric functions. The off-shell T-matrices are computed for the neutron–proton and neutron–deuteron systems. The limiting behaviours of our expression for the off-shell T-matrix are verified and found correct. [ABSTRACT FROM AUTHOR]

The aim of this paper is to introduce a method for enhancing the nonlinear optical properties in silica glass by using metallic nanoparticles. First, the T-matrix method is developed to calculate the effective dielectric constant for the compound of silica glass and metallic nanoparticles, both of which possess nonlinear dielectric constants. In the second step, the Maxwell-Garnett theory is exploited to replace the spherical nanoparticles with cylindrical and ellipsoidal ones, facilitating the calculation of the third-order nonlinear effective susceptibility for a degenerate four-wave mixing case. The results are followed by numerical computations for silver, copper and gold nanoparticles. It is shown, graphically, that the maximum and minimum of the real part of the reflection coefficient for nanoparticles of silver occurs in smaller wavelengths compared to that of copper and gold. Further, it is found that spherical nanoparticles exhibit greater figure-of-merit compared to those with cylindrical or ellipsoidal geometries. [ABSTRACT FROM AUTHOR]

By exploiting the theory of ordinary differential equations together with certain properties of higher transcendental functions, a useful analytical expression for the integral transform of the Green's function for motion in Coulomb-Yamaguchi potential is derived via the r-space approach. This integral transform is applied to construct an analytical expression for off-shell Jost solution in its 'maximal reduced form' involving confluent and Gaussian hypergeometric functions. Corresponding Jost functions automatically follow from this solution. Finally, as another application of the off-shell Jost solution, the off-shell T-matrix is calculated by using a modified relation between off-shell physical wave function and T-matrix which does not involve the potential explicitly, thereby avoiding certain difficult integrals, and expressed it in terms of rational functions and simple hypergeometric functions which is in exact agreement with the results given previously by other authors. [ABSTRACT FROM AUTHOR]

Using a tight-binding model and a transfer-matrix technique, we numerically investigate the effects of the coupling strength and the role of solitons on the electronic transmission through a system in which trans-polyacetylene (trans-PA) molecule is sandwiched between two semi-infinite single-walled carbon nanotubes (SWNT). We rely on Landauer formalism as the basis for studying the conductance properties of this system. Our calculations show that the solitons play an important role in the response of this system causing a large enhancement in the conductance. Also our results suggest that the conductance is sensitive to the CNT/molecule coupling strength. [ABSTRACT FROM AUTHOR]