Exciton binding energies in CdTe/Cd 1−xMn xTe multiple quantum wells

Abstract

These results are compared with binding energies calculated with a variational approach which accounts for motion along the z-direction as well as in the x-y plane. The 1S and 2S states of both light hole, (e 1, ℓ 1), and heavy hole (e 1h 1) excitons have been observed in CdTe/Cd 1−xMn xTe multiple quantum wells. Clear identification of the 2S states arises from their large diamagnetic effects and their observation has allowed the light and heavy hole exciton binding energies to be investigated with changes in depth of the electron and hole confining potentials by application of a magnetic field. In a sample with x ∼ 0.75 it is found that changes of the heavy hole exciton binding energies are small, ⪅ 1 2 meV, even for large changes, ≈40 meV, of the hole confining potential. For the light hole exciton changes of the binding energy are larger, ≅ 2meV, for smaller changes, ≅ 14meV, of the hole confining potential.