Green-function calculations of coherent electron transport in a gated Si nanowire

We describe a detailed numerical scheme to calculate electron transport in quantum wires using the Green function formalism combined with tight-bindin g orbital basis, As an example of the application, we study the electron tr ansport in a Si nanowire containing a finite potential barrier. The effects of nonzero bias, temperature, and disorder on the barrier-induced oscillat ory conductance are investigated within the context of coherent transport m odel The oscillatory behavior of the conductance as a function of the Fermi energy is found to be highly sensitive to sample disorder and limited to a very low temperature and a small bias range.