Transport in models with correlated diagonal and off-diagonal disorder

The electrical transport properties of one-dimensional tight-binding models, with correlation between diagonal and off-diagonal disorder, are obtained using Felderhof's method. A new local transformation eliminating the off-diagonal disorder is utilised. The characterisation of the type of correlation for the existence of a critical energy E_c, at which transmission exists, is found. It is a generalisation, in some sense, of the well known transmission at the band centre for the case with only off-diagonal disorder. For the high-wavenumber approximation we find explicitly the inverse localisation length which, close to E_c, behaves as mod E-E _c mod ^nu, with nu =1 at the edges of the band and nu =2 otherwise. The transmission for a wavepacket around E_c is analysed for samples of finite size.