ABSTRACT
Γ-X intervalley interlayer electron tunneling in a AlAs/GaAs/AlAs (001) double-barrier structure has been investigated using the tunneling formalism based on the non-equilibrium Green's function technique. The effects of indirect bandgap, band non-parabolicity, multi-orbitals in the aperiodic layered structure is taken into account by the Green's function formulation of scattering theory incorporated with the multi-orbital tight-binding model. The high external bias effect on the junction is solved exactly within this model. The effect of the X valley originated barrier confined states on the electron tunneling are analyzed with the spectral local density of states of the double-barrier structure in the [001] direction under the external bias. The smaller current peak to valley ratios are found in the double-barrier structures with thicker barriers, which is consistent with the experimental results. The enhancement of Γ-X interlayer intervalley electron transfer and reduction of the Γ-Γ resonant electron interlayer transfer is found with the increase of the phenomenological imaginary potential term.
