arXiv subjects

Wallas S. Nascimento

Publications and source records attributed to Wallas S. Nascimento.

4 recordsLinked to original sources

arXiv2024

Electron Confinement study in a double quantum dot by means of Shannon Entropy Information

In this work, we use the Shannon informational entropies to study an electron confined in a double quantum dot; we mean the entropy in the space of positions, $S_r$, in the space of momentum, $S_p$, and the total entropy, $S_t = S_r+S_p$. We obtain $S_r$, $S_p$ and $S_t$ as a function of the parameters $A_2$ and $k$ which rules the height and the width, respectively, of the internal barrier of the confinement potential. We conjecture that the entropy $S_r$ maps the degeneracy of states when we vary $A_2$ and also is an indicator of the level of decoupling/coupling of the double quantum dot. We study the quantities $S_r$ and $S_p$ as measures of delocalization/localization of the probability distribution. Furthermore, we analyze the behaviors of the quantities $S_p$ and $S_t$ as a function of $A_2$ and $k$. Finally, we carried out an energy analysis and, when possible, compared our results with work published in the literature.

physics.atom-ph↗

arXiv2021

Coulomb Correlation and Information Entropies in Confined Helium-Like Atoms

The present work studies aspects of the electronic correlation in confined H$^{-}$, He and Li$^+$ atoms in their ground states using the informational entropies. In this way, different variational wavefunctions are employed in order of better take account of Coulomb correlation. The obtained values for the $S_r$, $S_p$ and $S_t$ entropies are sensitive in relation to Coulomb correlation effects. In the strong confinement regime, the effects of the Coulomb correlation are negligible and the employment of the models of independent particle and two non-interacting electrons confined by a impenetrable spherical cage gains importance in this regime. Lastly, energy values are obtained in good agreement with the results available in the literature.

physics.atom-ph↗

arXiv2019

Information and quantum theories: an analysis in one-dimensional systems

We pedagogically present the information theory as originally established, explaining its essential ideas and paying attention to the expression employed to measure the amount of information. Also we discussed relationships between information and quantum theories. In this context we determined the information entropies on position, $S_x$, and momentum, $S_p$, spaces, besides the entropy sum $S_t$. Here, we use the modified entropic expressions that are dimensionally consistent. We provide original explanations for the behaviors of the $S_x$, $S_p$ and $S_t$ values analyzing the probability densities and by means of the normalization constants and properties of Fourier transform. We validate the entropic uncertainty relation and inspect the standard deviation and information entropies as measures of quantum uncertainty. The systems of interest unidimensional one-article quantum systems in ground and excited states.

quant-ph↗

arXiv2017

Shannon entropy: a study of confined hydrogenic-like atoms

The Shannon entropy in the atomic, molecular and chemical physics context is presented by using as test cases the hydrogenic-like atoms $H_c$, ${He_c}^+$ and ${Li_c}^{2+}$ confined by an impenetrable spherical box. Novel expressions for entropic uncertainty relation and Shannon entropies $S_r$ and $S_p$ are proposed to ensure their physical dimensionless characteristic. The electronic ground state energy and the quantities $S_r$, $S_p$ and $S_t$ are calculated for the hydrogenic-like atoms to different confinement radii by using a variational method. The global behavior of these quantities and different conjectures are analyzed. The results are compared, when available, with those previously published.

physics.atom-ph↗