A theoretical study of the terahertz dynamics of magnetoexcitons in GaAs-(Ga,Al)As quantum wells

Recent experimental measurements obtained via a highly sensitive optically detected resonance technique have shown that magnetoexcitons in GaAs-(Ga,Al)As semiconductor quantum wells (QWs) have discrete internal energy levels, with transition energies found in the far-infrared (terahertz) region. This work presents a theoretical study of some internal exciton transitions of light- and heavy-hole confined magnetoexcitons in GaAs-(Ga,Al)As QWs under magnetic fields applied in the growth direction of the semiconductor heterostructure. We use a variational procedure in the effective-mass approximation, and a parabolic dispersion for electrons, and assume the spin-orbit splitting to be large enough so that the interaction between J = 3/2 and J = 1/2 hole states may be disregarded. The 1s --> 2s and 1s --> 2p(+) theoretical transitions are in good agreement with optically detected resonance measurements for far-infrared intraexcitonic transition energies in GaAs-(Ga,AI)As QWs.