New effects of structure in momentum and real space on nonlinear transport across heterojunction band discontinuities

Nonlinear transport across heterojunction band discontinuities in strong electric fields is theoretically investigated. New phenomena which depend on the combined effects of the structure in real and momentum space are found. Reflections at the heterointerfaces, carrier overheating at the potential step, and the L→Γ, X→Γ backscattering bottlenecks produce pronounced peaks and anisotropies in the energy and momentum distributions, respectively. Finally, a new ionization rate overshoot effect due to the band structure difference between the two materials is discussed.