Department of Physics & Materials Science: Recent submissions
Now showing items 81-100 of 164
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Analytical Absorption Cross-Section for Photon by a Hydrogen 2s Atom
(IOP Publishing, 2011-04)We calculate the absorption cross-section for photon by a hydrogen 2s atom using the quantum-classical approximation for the total photo cross-section of many electron atoms. With the application of the first-order term ... -
Ultracold Atom-Ion Systems in Hybrid Traps
(Humboldt-Universität zu Berlin, 2017-11-21)This thesis deals with the theoretical description of a hybrid system of an ultracold neutral atom and a single ion. These hybrid atom-ion systems combine the key advantages of ultracold neutral atoms and ions. In particular, ... -
Symmetry Dependent Analytical Pseudopotential for Helium Atom
(2019-11-11)Electron-electron interaction is the origin of the many-body problems usually encountered in physics and chemistry. Helium atom and other two-electron systems are the simplest many-body systems in nature. The Schr¨odinger ... -
Multipole expansion of integral powers of cosine theta
(Nature Publishing Group, 2020-11-18)Legendre polynomials form the basis for multipole expansion of spatially varying functions. The technique allows for decomposition of the function into two separate parts with one depending on the radial coordinates only ... -
Ultracold Atom-Ion Systems in Hybrid Traps
(Humboldt-Universität zu Berlin, 2017-11-21)This thesis deals with the theoretical description of a hybrid system of an ultracold neutral atom and a single ion. These hybrid atom-ion systems have attracted significant interest in recent years. They combine the key ... -
Near-Exact Non-relativistic Energies for Many-Electron Atoms
(2017-12)Electron-electron interactions and correlations form the basis of difficulties encountered in the theoretical solution of problems dealing with multi-electron systems. Accurate treatment of the electron-electron problem ... -
A study of the Equatorial Ionosphere over Nairobi During selected magnetically disturbed and quiet times for the year 2009 Using co-located instruments
(ARC, 2014)Investigation of the behavior of the Equatorial Ionosphere over Nairobi-Kenya within the East Africa region is done using co-located instruments, that is, SCINDA-GPS system and a Magnetometer ( MAGDAS). This was done for ... -
Complex Spacetime Frame: Four-Vector Identities and Tensors
(Scientific Research Publishing, 2014)This paper provides derivation of some basic identities for complex four-component vectors defined in a complex four-dimensional spacetime frame specified by an imaginary temporal axis. The resulting four-vector identities ... -
Some new features of photon statistics in a fully quantized parametric amplification process
(Scientific Research Publishing, 2014)An exact quantum treatment reveals that signal and idler photon number operators are not wellbehaved dynamical operators for studying photon statistics in parametric amplification/downconversion processes. Contrary to ... -
Exact analytical solutions for fully quantized parametric oscillation dynamics
(Routledge, 2013)In this paper, a simple method for obtaining general analytical solutions of the time evolution equations for a fully quantized parametric oscillation process is developed. Heisenberg’s equations for the signal–idler photon ... -
A Direct Calculation of First-Order Wave Function of Helium
(IOP Publishing, 2010)We develop a simple analytic calculation for the first order wave function of helium in a model in which nuclear charge screening is caused by repulsive coulomb interaction. The perturbation term, first-order correlation ... -
Generalized relativistic dynamics in a non-inertial reference frame
(Springer-Verlag, 2010)Generalized relativistic field equations have been derived for dynamics in a non-inertial reference frame interpreted as a Finsler space where events are specified by both spacetime coordinates and corresponding velocities ... -
Revisiting non-degenerate parametric down-conversion
(Springer-Verlag, 2008)he quantum dynamics of a two-mode non-resonant parametric down-conversion process is studied by recasting the time evolution equations for the basic operators in an equivalent spin equation form with simpler exact solutions ... -
Complex Spacetime Frame: Four-Vector Identities and Tensors
(Scientific Research Publishing, 2014)This paper provides derivation of some basic identities for complex four-component vectors defined in a complex four-dimensional spacetime frame specified by an imaginary temporal axis. The resulting four-vector identities ... -
First Order Expectation Values of Electron Correlation Operators for Two-Electron Atoms
(SPG, 2015)Simple analytic first-order wave functions corresponding to two-electron atoms electron correlation operators are obtained by reduction of the Rayleigh-Schrödinger first order perturbation equation to that of one-electron ... -
Progressively accurate WKB approximations through factorization and successive boost transformations
(Research gate, 2015)This paper develops a procedure for obtaining progressively improving approximate solutions of the WKB (semiclassical ) model of the stationary Schroedinger equation through factorization and successive boost transformations ... -
Composite Hermite and Anti-Hermite Polynomials
(Scientific Research Publishing, 2015)The Weber-Hermite differential equation, obtained as the dimensionless form of the stationary Schroedinger equation for a linear harmonic oscillator in quantum mechanics, has been expressed in a generalized form through ... -
Quantum thermodynamics of a strongly interacting bose-fermi mixture in a three-dimensional anharmonic potential
(Research gate, 2016)ABSTRACT Thermodynamic properties of Bose-Fermi mixture at ultra-low temperatures were studied using perturbation theory in three Cartesian coordinates. The Hamiltonian for the mixture was developed in terms of boson-boson, ... -
On a complex spacetime frame: new foundation for physics and mathematics
(Research gate, 2016)This paper provides a derivation of a unit vector specifying the temporal axis of four-dimensional space-time frame as an imaginary axis in the direction of light or general wave propagation. The basic elements of the ... -
Fundamental quantum noise in a fully quantized degenerate parametric amplification process
(Research gate, 2016)An exact analytical solution of the time-dependent Schroedinger equation for a fully quantized degenerate parametric amplification process generated by quantized multi-mode pump photons provides a quantized multi-photon ...
