Theoretical study on density of states for heavy-hole exciton in a microtube of GaAs/AlGaAs

We studied a heavy-hole exciton in a microtube that contains two GaAs/AlGaAs quantum wells in a section of the tube layer and calculated its ground-state energy and exciton density of states those theoretical results are in agreement with an experimental case.The exciton trial function is taken as a product of the ground state wave functions of both the unbound electron and the hole in the heterostructure, with a correlation function that depends only on electron-hole separation. A renormalized Schrödinger equation for the correlation function is derived and coincides with the corresponding equation for a hydrogen atom in an effective isotropic and non-homogeneous space. The binding energy of the ground state for an exciton in this heterostructure is calculated by the variational model. The contribution to the energy given by the sublevels and the density of states is determined as a function of the width of the well, the aluminum concentration and the position of the quantum wells in the microtube. Additionally, profiles of the confinement potentials such as rectangular, soft and parabolic have been used.