Binding of biexcitons in GaAs/AlxGa1−

Abstract

Properties of the heavy-hole excitons and biexcitons in GaAs/Al 0.3 Ga 0.7 As superlattices are studied using linear and nonlinear optical techniques. In superlattices with miniband halfwidths less than the exciton binding energy, the biexciton binding energy is found to be the same as in the noninteracting multiple quantum wells of the same width. When the miniband halfwidth exceeds the exciton binding energy, the biexciton binding energy decreases abruptly to the bulk value. ͓S0163-1829͑97͒02008-0͔

Coherent dynamics of interwell excitons in GaAs/AlxGa1−Mizeikis1, Birkedal2, Langbein3 et al. 1997Phys. Rev. BSelf Cite3000View full textAdd to dashboardCite

“…The high biexciton binding energy of 2.4 meV in the superlattice is essentially the same as was found in noninteracting multiple quantum wells with L w ϭ80 Å. 12 This is an indication that the heavy-hole biexcitons as well as the excitons are mainly localized inside the quantum well and are thus quasi-two-dimensional states.…”

“…The HHX binding energy in 80-Å-wide noninteracting multiple quantum wells E x b(2D) was determined earlier 12 to be Ϸ10 meV. These values show that the investigated sample falls into the category of narrowminiband superlattices.…”

“…12 Hence, the onset of the HHX continuum transitions is just above the IWX resonance. In the TFWM measurements with subpico- second time resolution, it is not possible to excite selectively only the IWX exciton.…”

Composition dependence of the interband critical points in Si1−xGex alloys: A fractional–dimensional space approach

“…16 -21 This technique has also been used to study biexcitons, [22][23][24] excitonphonon interactions, 25 the Stark shift of excitonic complexes, 26 the refractive index, 27 impurity states, 28 -30 the Pauli blocking effect, 31 and the polaron effect 32 in quantum wells. In the fractional-dimensional space approach, an anisotropic interaction in a three-dimensional space is treated as an isotropic one in a lower effective-order fractionaldimensional space, the dimension of which provides a measure for the degree of the anisotropy in the actual physical system.…”

Binding of Biexcitons in GaAs/AlGaAs Superlattices

“…1 show superlattice formation, we have calculated the excitor binding energies using the fractional-dimensional approach [9] (see [10], for more details). Parameters of GaAs, required for the calculations, were taken from literature [ΙΙ], and k.p band-structure calculations.…”