34 citations · 136 across the 11 of their papers we have counts for
11 papers
Two-electron resonances in quasi-one dimensional quantum dots with Gaussian confinement
Arkadiusz Kuroś, Anna Okopińska
We consider a quasi one-dimensional quantum dot composed of two Coulombically interacting electrons confined in a Gaussian trap. Apart from bound states, the system exhibits resona…
Entanglement entropies in the ground states of helium-like atoms
Przemyslaw Koscik, Anna Okopinska
We examine the entanglement in the ground states of helium and helium-like ions using an original Hylleraas expansion. The von Neumann and linear entropies of the reduced density m…
Coupled anharmonic oscillators: the Rayleigh-Ritz approach versus the collocation approach
Arkadiusz Kuros, Anna Okopinska
For a system of coupled anharmonic oscillators we compare the convergence rate of the variational collocation approach presented recently by Amore and Fernandez (2010 Phys.Scr.81 0…
The optimized Rayleigh-Ritz scheme for determining the quantum-mechanical spectrum
Przemyslaw Koscik, Anna Okopinska
The convergence of the Rayleigh-Ritz method with nonlinear parameters optimized through minimization of the trace of the truncated matrix is demonstrated by a comparison with analy…
Two-electron entanglement in elliptically deformed quantum dots
Przemyslaw Koscik, Anna Okopinska
Entropic entanglement measures of a two-dimensional system of two Coulombically interacting particles confined in an anisotropic harmonic potential are discussed in dependence on t…
Quasi-exact solutions for two interacting electrons in two-dimensional anisotropic dots
Przemyslaw Koscik, Anna Okopinska
We present an analysis of the two-dimensional Schrodinger equation for two electrons interacting via Coulombic force and confined in an anizotropic harmonic potential. The separabl…
Application of the Frobenius method to the Schrodinger equation for a spherically symmetric potential: anharmonic oscillator
Przemyslaw Koscik, Anna Okopinska
The power series method has been adapted to compute the spectrum of the Schrodinger equation for central potential of the form $V(r)={d_{-2}\over r^2}+{d_{-1}\over r}+\sum_{i=0}^{\…
Gaussian approximation to the condensation of the interacting Bose gas
Anna Okopińska
The effective action formalism of quantum field theory is used to study the properties of the non-relativistic interacting Bose gas. The Gaussian approximation is formulated by cal…
The Fokker-Planck equation for bistable potential in the optimized expansion
Anna Okopińska
The optimized expansion is used to formulate a systematic approximation scheme to the probability distribution of a stochastic system. The first order approximation for the one-dim…
The Effective Action for Local Composite Operators and
Anna Okopińska
The generating functionals for the local composite operators, and , are used to study excitations in the scalar quantum field theory with interaction. The e…
Optimized Perturbation Methods for the Free Energy of the Anharmonic Oscillator
Kostas Vlachos, Anna Okopinska
Two possibile applications of the optimized expansion for the free energy of the quantum-mechanical anharmonic oscillator are discussed. The first method is for the finite temperat…