High-pressure magnetotransport measurements of resonant tunnelling via X-minimum related states in AlAs barrier

In this paper, we present the results of magnetotransport experiments perfo rmed on a single barrier GaAs/AlAs/GaAs heterostructures. Tunnel current wa s measured as a function of magnetic field for different values of bias vol tage and hydrostatic pressure. We observed that the amplitude of the magnet ooscillations of tunnel current quenched when the requirements for resonant tunnelling were met and it recovered in out-of-resonance conditions. This effect was observed both for tunnelling through donor states and through X- minimum related quasiconfined conduction band states. The fact that also in the latter case the amplitude was restored suggests that this process invo lved X-z subbands and took place without a participation of phonons (the so -called k(parallel to)-conserving process).