Theory of transmission through disordered superlattices

We derive a theory for transmission through disordered finite superlattices in which the interface roughness scattering is treated by disorder averagi ng. This procedure permits efficient calculation of the transmission throug h samples with large cross sections. These calculations can be performed ut ilizing either the Keldysh or the Landauer-Buttiker transmission formalisms , both of which yield identical equations. For energies close to the lowest miniband, we demonstrate the accuracy of the computationally efficient Wan nier-function approximation. Our calculations indicate that the transmissio n is strongly affected by interface roughness and that information about sc ale and size of the imperfections can be obtained from transmission data. [ S0163-1829(99)01946-3].