“…The in-plane Hamiltonian [H 2D (r e , r h )] describes the electron and hole motion in the xy plane in a nonhomogeneous magnetic field, which is represented by the vector potential A(r). We will make use of a variational approach 19 to assume that the difference between the 2D and 3D Coulomb interactions [W (r, z e,h )] can be made very small by the choice of an optimum value for γ, 20 which is a variational parameter that is calculated from the average of W (r, z e,h ) over the exciton wave function. The perpendicular contribution [H ⊥ (z e,h )] describes the exciton confinement in the quantum well, i.e., in the z direction, which is not affected by the magnetic field.…”