Effect of external uniaxial stress on the electronic properties and symmetry of p-GaAs/AlxGa1−xAs quantum wells

The results of experimental and theoretical investigations of the energy spectrum and electronic properties of symmetric p-[001] Al 0.5 Ga 0.5 As/GaAs/Al 0.5 Ga 0.5 As heterostruc-tures under uniaxial [110] compression are presented. The stress-induced piezoelectric field breaks the confining potential symmetry in the quantum well and lifts the degeneracy of the hole subbands. A redistribution of holes in the spin subbands of the ground state takes place, which is revealed in the different shifts of the Shubnikov-de Haas oscillation maxima corresponding to the different spin subbands. The [110] uniaxial compression significantly modifies the band structure, which leads to a strong aniso-tropy of the Fermi surface. The electrical resistance becomes strongly anisotropic under applied compression, decreasing in the direction parallel to the compression and increasing in the perpendicular direction.