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 sp ectrum and electronic properties of symmetric p-[001] Al0.5Ga0.5As/GaAs/Al0 .5Ga0.5As heterostructures under uniaxial [110] compression are presented. The stress-induced piezoelectric field breaks the confining potential symme try in the quantum well and lifts the degeneracy of the hole subbands. A re distribution of holes in the spin subbands of the ground state takes place, which is revealed in the different shifts of the Shubnikov-de Haas oscilla tion maxima corresponding to the different spin subbands. The [110] uniaxia l compression significantly modifies the band structure, which leads to a s trong anisotropy of the Fermi surface. The electrical resistance becomes st rongly anisotropic under applied compression, decreasing in the direction p arallel to the compression and increasing in the perpendicular direction.