Donor impurity-related linear and nonlinear intraband optical absorption coefficients in quantum ring: effects of applied electric field and hydrostatic pressure

Abstract

The linear and nonlinear intraband optical absorption coefficients in GaAs three-dimensional single quantum rings are investigated. Taking into account the combined effects of hydrostatic pressure and electric field, applied along the growth direction of the heterostructure, the energies of the ground and first excited states of a donor impurity have been found using the effective mass approximation and a variational method. The energies of these states are examined as functions of the dimensions of the structure, electric field, and hydrostatic pressure. We have also investigated the dependencies of the linear, nonlinear, and total optical absorption coefficients as a function of incident photon energy for several configurations of the system. It is found that the variation of distinct sizes of the structure leads to either a redshift and/or a blueshift of the resonant peaks of the intraband optical spectrum. In addition, we have found that the application of an electric field leads to a redshift, whereas the influence of hydrostatic pressure leads to a blueshift (in the case of on-ring-center donor impurity position) of the resonant peaks of the intraband optical spectrum.

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

“…Most of those investigations were made for spherical quantum dots systems (see for instance Refs. [9,40,41]) and there are also works on single quantum rings structures [20,42,43]. In our case, the nonlinear coefficient function on photon energy contributes to the clearly observable shift of the total absorption coefficient maximum value from the corresponding threshold energy point and to the nonmonotonic behavior of absorption strength as the function of L 2 .…”

“…All this leads to conclude that the features of the donor impurity complex in a unique geometry like the concentric double QRs conditions this particular optical response whose physical reason lies on the magnitude of the expected intra-and inter-state values of the electric dipole moment. These authors have not found in the literature a similar behavior of the nonlinear optical absorption coefficient in reports involving nonlinear impurity-related absorption [9,20,40]. Most of those investigations were made for spherical quantum dots systems (see for instance Refs.…”

“…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]. Xie has investigated the linear and the third-order nonlinear optical absorption spectra of a donor impurity confined within a QR with a parabolic potential [18].…”

“…According to the results, the second-order nonlinear optical rectification coefficient of a hydrogenic QR is strongly affected by the geometrical size and chemical potential of the pseudopotential, the position of the hydrogenic impurity, and the external magnetic field. There is also a recent report on the combined influence of hydrostatic pressure and ingrowth-direction applied electric field on the donor-related linear and nonlinear optical absorption in a GaAs three-dimensional single quantum ring [20]. There, the authors have shown that the behavior of the energies of the ground and excited statesand, as a consequence, the position of the maximum of the optical absorption related with the corresponding interstate transitionsstrongly depend on the hydrostatic pressure, applied electric field strength, and sizes of the structure.…”

Propiedades ópticas de impurezas donadoras en anillos cuánticos sometidos a los efectos combinados de campo eléctrico y radiación láser intensa no resonante

“…Estudios recientes han reportado el coeficiente de absorción óptica intrabanda lineal y no lineal en anillos cuánticos de GaAs aislados bajo los efectos de presión hidrostática y campo eléctrico (Barseghyan, et al, 2012). Entre los resultados arrojados en dicha investigación está que la variación de los diferentes tamaños característicos de la geometría de la estructura puede generar corrimientos bien sea al rojo o al azul de los picos resonantes del espectro óptico intrabanda.…”