Γ-Xinterference effects on quasi-bound-state lifetimes in GaAs/AlAs double-barrier heterostructures

The effect of {Γ}-X mixing on electron quasi-bound-state lifetimes in GaAs/AlAs symmetric double-barrier heterostructures is studied theoretically using an empirical tight-binding band-structure model. It is found that the {Γ} quasi-bound-state tunneling times can be shortened or lengthened by {Γ}-X mixing, depending on whether the AlAs barriers consist of an even or odd number of monolayers. This is attributed to the interference between the {Γ} and X conduction channels in the AlAs barriers.