Combined effects of intense laser field and applied electric field on exciton states in GaAs quantum wells: Transition from the single to double quantum well

Abstract

The effects of intense laser radiation on the exciton states in GaAs-Ga 1-x Al x As quantum wells are studied with the inclusion of applied dc electric fields oriented along the growth direction of the system. The calculations are made within the effective mass and parabolic band approximations. The intense laser effects have been included along the lines of the Floquet method, modifying the confinement potential associated to the heterostructure. The results for the exciton binding energy, the energy of the exciton-related photoluminescence peak, and the carriers overlap integral are presented for several configurations of the quantum well size, the strength of the applied electric fields, and the incident laser radiation.

In plane magnetic field and intense laser field effects on second harmonic generation of asymmetric AlGaAs/GaAs double quantum well

“…Now, in Fig. 3b) we report these curves for B = 0, that has the same crossing as for α 0 = 0; Then, with red dash-dot lines, we present the results for B = 5 T and we observe that the first energy crossing is for an smaller L lw value and it experiences a blueshift, and the second energy crossing increase further in the L lw QW width but now with a redshift; Finally we report the case for B = 10 T, in the region of L lw ∈ [2,16] and there is not any energy crossing, that will imply that the SHG resonant condition will not be fulfilled, at least not for chosen set of parameters.…”

“…E. Kasapoglu et al [15] also report, that due to ILF effect, the transition from semiparabolic QW to a kind of asymmetric double QW, affecting importantly the reported nonlinear optical properties, specifically the absorption coefficient and the relative refractive index change. Besides, C. A. Duque et al [16] investigated the combined effects of ILF and externally applied electric field on GaAs exciton states as the ILF modify the potential profile from single to double QW. On the other hand, for the situation α 0 < L/2, the potential profile deformation, as reported by E. C. Niculescu et al [17], is an analytical function of α 0 , in fact an arccos(α 0 ) one, and they reported the binding energy as well as the density of states for an impurity in a rectangular QW, as a function of the laser-dresser parameter and on the donor impurity position.…”

Exciton properties in zincblende InGaN-GaN quantum wells under the effects of intense laser fields

“…We consider, of interest, to highlight that the confining potential for holes in a In 0.2 Ga 0.8 N-GaN QW also experiences that kind of single-to-double QW transition at the value of α 0 reported in the current work. This is because such a feature is not present in the case, for instance, of a Ga 0.7 Al 0.3 As-GaAs QW, in which, for the same value of the ILF parameter, the shape of the conduction band profile is very similar with that of Figure 1 b [ 43 ]. Despite the greater value of the hole effective mass in the present system compared with that of the arsenide-based one, the main reason of such a difference lies in the height of the valence band confining barrier, which in the latter case is almost three times larger than the one formed in the nitride-based heterostructure studied here.…”

Exciton-related energies of the 1s-like states of excitons in GaAs-Ga1−xAlxAs double quantum wells

“…Optical processes in low dimensional semiconductors are affected by several factors such as applied electric and magnetic fields, hydrostatic pressure, confining potential, interface disorder, intense laser field radiation [1][2][3][4][5][6][7]. Among these phenomena, those related with exciton and impurity states are the most difficult to treat theoretically due to the lack of analytical expressions for the wave functions corresponding to the bound states of electron-hole pairs or electron-impurity centers, respectively.…”