Browsing by Author "W A Yahya"

Now showing 1 - 5 of 5
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    Entanglement fidelity for electron–electron interaction in strongly coupled semiclassical plasma and under external fields
    (2019-04-14) B J Falaye; K J Oyewumi; O A Falaiye; C A Onate; O J Oluwadare; W A Yahya
    This letter presents the effects of AB-flux field and electric field on electron–electron interaction, encircled by a strongly coupled semiclassical plasma. We found that weak external fields are required to perpetuate a low-energy elastic electron–electron interaction in a strongly coupled semiclassical plasma. The entanglement fidelity in the interaction process has been examined. We have used partial wave analysis to derive the entanglement fidelity. We found that for a weak electric field, the fidelity ratio for electron–electron interaction increases as the projectile energy increases, but remains constant or almost zero for a strong electric field. Our results provide invaluable information on how the efficiency of entanglement fidelity for a low-energy elastic electron–electron interaction in a strongly coupled semiclassical plasma can be influenced by the presence of external fields.
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    Predictions of the alpha-decay half-lives of even–even superheavy nuclei using modified Gamow-like model
    (2022-04-14) O K Azeez; W A Yahya; A A Saeed
    Abstract α-decay half-lives of superheavy nuclei have been studied using modified Gamow-like model and improved empirical formulas. The empirical formulas used in the study are Viola-Seaborg semi-empirical formula, universal decay law (UDL), Denisov-Khudenko formula (DK), Royer formula, Wang formula, AKRE formula, and new Ren B (NRB) formula. New values of the adjustable parameters in the modified Gamow-like model have been obtained using a least square fit scheme and input data from the NUBASE2020 database. We found that only two adjustable parameters are sufficient to describe the α-decay half-lives of heavy and superheavy nuclei. We also obtained new coefficients for the seven empirical formulas using similar procedure. The modified Gamow-like model (MGLM) and improved empirical formulas are then used to calculate the α-decay half-lives of measured superheavy nuclei with Z = 100–118. The calculated root mean square errors indicate that the Royer, DK, and AKRE formulas are the best three empirical formulas for evaluating the α-decay half-lives of the superheavy nuclei. The five best performing empirical formulas, together with the MGLM, are then used to predict alpha-decay half-lives of unmeasured even–even superheavy nuclei with Z = 120–126. The Q α values used for the predictions have been taken from the tabulated Weizs a ̈ cker-Skyrme-4 + RBF (WS4 + RBF) Q α values. The theoretical calculations suggest that N = 184 is a possible magic number, which is in agreement with previous theoretical calculations.
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    Pressure effects on the opto-electronic and mechanical properties of the double perovskite Cs2AgInCl6
    (2022-03-10) A A Sholagberu; W A Yahya; A A Adewale
    Abstract The double perovskite Cs2AgInCl6 is a potential material for the absorbing layer of a thin film solar cell due to its direct band gap. The only current limitation the material has is its wide band gap. A careful engineering of its structural, mechanical and opto-electronic properties with the aid of hydrostatic pressure ranging from 0 GPa16 GPa has been studied using density functional theory. The calculations were carried out using GGA-PBEsol (Perdew–Burke–Ernzerhof revised for solids) exchange correlation functional. It is found that the lattice constant reduces as the pressure increases, while the bulk modulus increases as the exerted pressure increases. The bulk moduli calculated from the elastic constants are found to be in agreement with those obtained via Birch-Murnaghan equation of state. This indicates the accuracy of the calculations, and it is achieved at all pressure values. The mechanical properties of the material are investigated, and the material is found to be anisotropic and ductile at all pressure considered. Due to the underestimation of the energy band gap by GGA-PBEsol exchange correlation functional, Tran-Blaha modified Burke Johnson (TB-mBJ), a metaGGA functional, was used to calculate the electronic and optical properties. The energy band gap is found to reduce from 2.746 eV at ambient pressure to 2.482 eV at 6 GPa and momentarily increases until it reached 2.501 eV at 16 GPa. The optical properties of Cs2AgInCl6 revealed its absorption threshold is in the visible range, although a shift in the absorption threshold is observed as pressure is applied on it. An 8.7 % increase in the refractive index is observed as pressure increases. The calculated absorption coefficient corresponds reasonably with the calculated band gap. The electron energy loss function and reflectivity of the material have also been investigated.
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