Third-order nonlinear absorption spectra of an impurity in a spherical quantum dot with different confining potential

Abstract

In this study, the linear and third-order nonlinear optical absorption coefficients of intersublevel transitions have been calculated for a spherical CdS/SiO 2 quantum dot (QD) with infinite and different finite confining potential by using the density matrix formalism. The electron eigenenergies and the corresponding wavefunctions have been determined by the variational method under the effective mass approximation. We have investigated the effects of the incident optical intensity, QD radius, and confinement potential on the intersublevel optical absorption coefficients. It is found that the size of the dot and depth of the confinement have a great effect on the linear, the nonlinear, and the total absorption coefficients. Also, the total optical absorption saturation intensity is controlled by the strength of the confinement or the incident optical intensity.

Exploring static and frequency-dependent third nonlinear polarizability of doped quantum dots driven by Gaussian white noise

“…In the present manuscript, we explore the role of Gaussian white noise on the diagonal components of the static and the frequency‐dependent third (second‐order) nonlinear polarizabilities ( and ) of doped QD. Recently, Şahin and coworkers made some significant contributions to a similar problem for a spherical QD and analyzed the role of impurity. The notable work of Karabulut and Baskoutas () also merits mention in a similar context, which includes the effect of electric field and impurity.…”

Influence of Gaussian white noise on the frequency-dependent first nonlinear polarizability of doped quantum dot

“…The confinement potential, in particular, sensitively modulates the physical properties of doped dots, and the structure of a) the confinement potential can be experimentally designed. 15,[39][40][41][42] A parabolic confinement potential is often appreciated as the suitable candidate to represent the potential in QD structures 2,8,16,28,31,33 and has been actually invoked in the study of optical properties of doped QDs. 18 The parabolic potential particularly becomes appropriate when the QDs are fabricated by etching process on a quantum well, ion implantation, or application of electrostatic gates.…”

Donor impurity-related linear and nonlinear optical absorption coefficients in GaAs/Ga1−xAlxAs concentric double quantum rings

“…λ 1s and λ 2s are variational parameters, and β is obtained from orthogonality condition between the hydrogenic wavefunctions in Eqs. (10) and (11). In order to find the impurity energies (E 1s and E 2s ) we just need to follow the usual variational procedure by minimizing 〈Ψ 1s jĤjΨ 1s 〉 and 〈Ψ 2s jĤjΨ 2s 〉 with respect to λ 1s and λ 2s , respectively [37].…”

“…Some authors studied the simultaneous effects of hydrogenic donor impurity and external perturbations, such as electric and magnetic fields and hydrostatic pressure, on the linear and nonlinear optical properties of semiconductor nanostructures, particularly in the case of semiconductor quantum dots [8][9][10][11][12][13][14][15][16][17]. There are also some research papers related with the effects of shallow-impurities and external influences on the linear and nonlinear optical properties in QRs [18][19][20].…”