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

In this paper, we present the results of magnetotransport experiments performed on a single barrier GaAs/AlAs/GaAs heterostructures. Tunnel current was measured as a function of magnetic field of different values of bias voltage and hydrostatic pressure. We observed that the amplitude of magnetooscillations 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 involved Xz subbands and took place without a participation of phonons (the so-called k||-conserving process. (author)