Spin-resolved resonant tunneling in a III-V semiconductor double-barrier structure

X-band-related resonant tunneling transport in a GaAs/AlAs double-barrier system has been investigated at 4.2 K in the presence of magnetic fields parallel to the current under hydrostatic pressures. Landau-level transitions between the GaAs Γ and the AlAs X confinement states are clearly identified. At very high pressures beyond the type-II transition and at high magnetic fields, the Landau-level transitions are further split into two peaks and this splitting can be understood in terms of resonant tunneling through spin-state Landau-levels of the collector AlAs X confinement state.