Application of the variations calculus on energy spectra of shallow   hydrogen-like impurities and excitons in GaAs/AlGaAs quantum wells
  A variational calculus method is applied for hydrogen-like impurities states and exciton states in AlGaAs/GaAs quantum wells within the effective masses approach. The hamiltonian is separated into radial and transversal parts to be considered and optimized using trial wavefunctions. The results satifsy the well-known cases of three-dimentional and two-dimentional hydrogen. The donor and exciton bound energy is shown to decrease while widthening the quantum well. The non-symmetrical donor position also decreases the bound energy. 
A. Gubanov, G. F. Glinskii
cond-mat.mtrl-sci