Hyperpolarizability of two electron atoms under exponential cosine screened coulomb potential

Abstract

Hyperpolarizability of two electron atoms He, Li+, Be2+, B3+, and C4+ embedded under quantum plasma environment has been calculated for the first time using exponential cosine screened coulomb potential (ECSCP) arising out of the interaction of atomic charge cloud with such an environment. Coupled Hartree-Fock theory within variational scheme has been utilised to estimate such nonlinear optical property for systematic variation of the screening parameter arising out of the coupling strength of the plasma with atomic charge cloud. Hyperpolarizability of the ions increases systematically with increase of the screening parameter. Results have been compared with respect to those obtained from the interaction of atomic systems with a Debye plasma environment giving rise to SCP. Interesting feature is observed for the polarizability and hyperpolarizability values under increasing screening parameters of ECSCP and SCP. Hyperpolarizability values for zero screening compare well with those available for the free ions.

Nonlinear response properties of atomic hydrogen under quantum plasma environment: A time‐dependent variation perturbation study on hyperpolarizability and two‐photon excitations

“…It is seen that IP decreases (and, thus, IPD increases) almost linearly as the plasma screening effect increases. In a screened potential, the linear, as well as nonlinear, polarizability values are increased substantially, [31,[66][67][68][69]85] resulting in the enhancement of different linear and NLO properties. The static dipole polarizability and hyperpolarizability values obtained from the zero frequency limit of their corresponding frequency-dependent counterparts are exactly solvable [30,88] for free H atom and are found to tally with our estimated values.…”

“…[31] However, such calculations on the hyperpolarizabilities of confined atomic systems are rather scanty and have been performed mostly on static hyperpolarizabilities. [64][65][66][67][68][69] Molecular static and dynamic first hyperpolarizabilities have been evaluated by de Wergifosse et al [70] Accurate density functional theory (DFT) calculations on linear and nonlinear electric properties of spatially confined molecules were performed by Chołuj et al [71] As molecules of different natures are, under many circumstances, surrounded by other environments, for example, solvent-solute systems or classical electrolytic environment, which has its origin for Debye shielding (SCP), it is worth mentioning the chemical implications of the present ideas with the existing literature. For example, extensive industrial applications of NLO organic, inorganic, and bio materials exist along with intrinsic theoretical understanding of macroscopic properties originating from electromagnetic field-induced NLO processes.…”

“…[ 31 ] However, such calculations on the hyperpolarizabilities of confined atomic systems are rather scanty and have been performed mostly on static hyperpolarizabilities. [ 64–69 ] Molecular static and dynamic first hyperpolarizabilities have been evaluated by de Wergifosse et al [ 70 ] Accurate density functional theory (DFT) calculations on linear and nonlinear electric properties of spatially confined molecules were performed by Chołuj et al [ 71 ]…”

“…The value of the screening constant that appears in ECSCP, mimicking the quantum plasma, [ 4 ] is chosen over a wide range starting from zero (ie, pure Coulomb potential) to a higher value for which the first two‐photon excited state remains barely bound. It is well established in linear response theory [ 66,69 ] that, for a given screening constant, the effect of quantum plasma on atomic energy levels is stronger than that due to classical plasma, and unbound energy levels are produced at comparatively lower screening parameters in ECSCP than in SCP. This has been corroborated here through the nonlinear response calculations of γ ( ω ) and two‐photon excited states.…”

Calculation of information entropies for the 1s2 state of helium‐like ions

“…For example, in addition to using YP in nuclear and elementary particles, [ 4 ] it is also used in calculating the bound and resonance states for one‐ [ 5–8 ] and two‐electron systems, [ 9,10 ] in scattering, [ 11 ] and in quantum entanglement. [ 12 ] ECSCP is used in calculating the bound and resonance states for one‐ [ 13,14 ] and two‐electron systems, [ 15–17 ] in plasma, [ 18 ] and scattering. [ 19,20 ]…”