Abstract
We report the determination of the symmetry of conduction-band states for type-II superlattices under on-axis and in-plane uniaxial stress. From their stress dependence, the symmetry of the electron states is labeled in terms of Xz or Xx,y conduction states. In some structures Xz is the conduction ground state and the ordering between Xz and Xx,y is reversed by in-plane stress. In others, this situation is reversed and an explanation of the results needs to take into account lattice matching of AlAs slabs to GaAs. The shear tetragonal deformation potential of X states in AlAs is obtained.