  Heterostructures made of transition metal oxides are new tailor-made
materials which are attracting much attention. We have constructed a 6-band k.p
Hamiltonian and used it within the envelope function method to calculate the
subband structure of a variety of LaAlO3/SrTiO3 heterostructures. By use of
density functional calculations, we determine the k.p parameters describing the
conduction band edge of SrTiO3: the three effective mass parameters, L=0.6104
eV AA^2, M=9.73 eV AA^2, N=-1.616 eV AA^2, the spin orbit splitting
Delta_SO=28.5 meV and the low temperature tetragonal distortion energy
splitting Delta_T=2.1 meV. For confined systems we find strongly anisotropic
non-parabolic subbands. As an application we calculate bands, density of states
and magnetic energy levels and compare the results to Shubnikov-de Haas quantum
oscillations observed in high magnetic fields. For typical heterostructures we
find that electric field strength at the interface of F = 0.1 meV/AA for a
carrier density of 7.2 10^{12} cm^-2 results in a subband structure that is
similar to experimental results.
