Computation of Complex Band Structures in Bulk and Confined Structures

Complex bands are computed for Si using a sp(3)d(5)s* atomistic tight binding Hamiltonian with spin orbit splitting for both bulk and confined structures. Representative band structures are shown. The bulk Si calculations imply that band-to-band tunneling current should be less in the [1 0 0] direction compared to either [1 1 0] or [1 1 1] directions, which is qualitatively consistent with experiment.