A. M. Savin

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

Abstract The results of experimental and theoretical investigations of the energy spectrum and electronic properties of symmetric p-[001] Al0.5Ga0.5As/GaAs/Al0.5Ga0.5As 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.

Mobility anisotropy of two-dimensional hole gases in (001)GaAs/Al0.5Ga0.5As heterostructures and the influence of uniaxial compression

Transport properties of 2D hole gases in (001)GaAs/Al0.5Ga0.5As heterostructures in the [1 = 10] and [110] directions have been investigated. In-plane uniaxial compression up to 5 kbar was applied in one or the other of the two directions, and measurements were performed in the temperature range 1.4 - 60 K and in a magnetic field up to 6 T. Without uniaxial compression the mobility is largest in the [1 = 10] direction, the [1 = 10]:[110] mobilities ratio attaining its largest values at low temperatures and high carrier densities. Interface roughness scattering together with acoustic phonon scattering is suggested to be the underlying phenomenon. Under uniaxial compression the electrical resistance decreases in the direction parallel to the compression, and it increases in the direction perpendicular to the compression. This behaviour is found to be in qualitative agreement with recent band structure calculations.

POSITIVE MAGNETORESISTANCE AND HOLE-HOLE SCATTERING IN GAAS/AL0.5GA0.5AS HETEROSTRUCTURES UNDER UNIAXIAL COMPRESSION

Resistance, magnetoresistance and their temperature dependencies have been investigated in the 2D hole gas at a [001] p-GaAs/Al

Piezoelectric effect and the long-term resistance relaxations induced by uniaxial compression in p-GaAs/AlxGa1−x as heterostructures

_{0.5}

Positive delayed photoconductivity in double heterostructures Al0.5Ga0.5As/GaAs/Al0.5Ga0.5As of the p-type

Ga

Anisotropy of Long-term Resistivity Relaxations Induced in p -(0 0 1)GaAs/Al 0.5 Ga 0.5 As by Uniaxial Stress

_{0.5}

Persistent photoconductivity in p-type Al0.5Ga0.5As/GaAs/Al0.5Ga0.5As heterostructures

As heterointerface under [110] uniaxial compression. Analysis performed in the frame of hole-hole scattering between carriers in the two spin splitted subbands of the ground heavy hole state indicates, that h-h scattering is strongly suppressed by uniaxial compression. The decay time

Positive persistent photoconductivity in p-type Al0,5Ga0,5As/GaAs/Al0,5Ga0,5As

tau_{01}

Negative and persistent photoconductivity in p-type Al0.5Ga0.5As/GaAs/Al0.5Ga0.5As heterostructures under uniaxial stress

of the relative momentum reveals 4.5 times increase at a uniaxial compression of 1.3 kbar.

Light and electric field influence on resistivity and long-term relaxations of piezoresistivity in p-GaAs/Al0.5Ga0.5As heterostructures

AbstractLong-term resistance relaxations induced by uniaxial compression in (001)p-GaAs/Al0.5Ga0.5 As heterostructures are observed, and the main properties of these relaxations are investigated: the dependence of their character on the direction of the uniaxial compression, the change in concentration of current carriers during the relaxation processes, and the quenching of the relaxations by temperature, illumination, and high electric fields. It is found that the character of the relaxation process is different for compression directions [110] and n