EFFECT OF UNIAXIAL COMPRESSION ON QUANTUM HALL PLATEAUS AND SHUBNIKOV-DE HAAS OSCILLATIONS IN P-TYPE GAAS/ALXGA1-XAS HETEROSTRUCTURES

Quantum Hall effect and Shubnikov--de Haas oscillations in a two-dimensional hole gas at a p-type GaAs/${\mathrm{Al}}_{0.5}$${\mathrm{Ga}}_{0.5}$As(001) interface show that under in-plane (110) uniaxial compression a redistribution of carriers between the two spin-split subbands of the heavy-hole ground state takes place. At the maximal compression of 2.5 kbar the carrier density of the most populated subband is decreased by 18%, while the total carrier density remains almost unchanged. A decrease of the spin splitting under the uniaxial compression is proposed. \textcopyright{} 1996 The American Physical Society.