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Bouchra El Alaoui

Publications and source records attributed to Bouchra El Alaoui.

2 recordsLinked to original sources

Dynamics of nonclassicality in a generalized Tavis Cummings model with XY spin $(1/2,1)$ atomic interactions

We investigate the dynamics of nonclassicality, quantified by the Wigner Yanase skew information, in generalized Jaynes Cummings (JC) and Tavis Cummings (TC) models describing light matter interactions in cavity quantum electrodynamics. We first analyze a generalized JC model consisting of a single bosonic cavity mode coupled to a spin 1 atom, focusing on the temporal evolution of nonclassicality in both the cavity field and the atomic subsystem. We then extend this framework to a generalized TC model by introducing an additional spin $1/2$ atom, enabling us to examine the influence of collective atomic degrees of freedom. The global dynamics are investigated both with and without an $XY$ spin interaction. Our results show that, under resonance conditions, the system exhibits efficient excitation exchange between the cavity field and the atomic subsystem, resulting in regular, coherent nonclassicality dynamics and enhanced field nonclassicality generation. Conversely, an increasing longitudinal magnetic field acts primarily as an effective detuning parameter rather than a direct exchange interaction. In this off resonant regime, the atom field coupling is substantially weakened, localizing excitations within the atomic subsystem. This localization suppresses coherent energy transfer to the cavity field, leading to a pronounced reduction in field nonclassicality, while the atomic subsystem retains the majority of the quantum correlations. Notably, atomic superposition states exhibit highly irregular spin dynamics, reflecting a detuning-induced redistribution of quantum correlations. These findings demonstrate that the dynamics of spin and field nonclassicality are governed primarily by interaction mediated excitation flow and resonance conditions rather than the initial energy distribution alone, ..

quant-ph↗

Parity symmetry breaking of spin-$j$ coherent state superpositions in Gaussian noise channel

The Wigner function and Wigner-Yanase skew information are connected through quantum coherence. States with high skew information often exhibit more pronounced negative regions in their Wigner functions, indicative of quantum interference and non-classical behavior. Thus, the relationship between these two concepts is that states with high quantum coherence tend to display more non-classical features in their Wigner functions. By exploiting this relationship, which manifests as parity symmetry and asymmetry, we analyze parity symmetry and asymmetry in the superposition of two spin coherent states for a spin-$1/2$, as well as for a general spin-$j$. This analysis shows that the preservation of the parity asymmetry, or the violation of the parity symmetry, correlates with an increase in the value of spin $j$. Additionally, we investigate the behavior of parity symmetry and asymmetry of these states subjected to a Gaussian noise channel. Specifically, we examine how this parity symmetry and asymmetry change and identify the points at which parity symmetry is violated in the spin-$1/2$ cat state. Notably, the violation of parity symmetry becomes more pronounced at higher values of the decoherence parameter $s$. Our study shows how the spin value $j$ affects the breaking of parity symmetry in general spin-$j$ cat states that are hit by Gaussian noise.

quant-ph↗