Off-diagonal disorder in the Anderson model of localization

We examine the localization properties of the Anderson Hamiltonian with add itional off-diagonal disorder using the transfer-matrix method and finite-s ize scaling. We compute the localization lengths and study the metal-insula tor transition (MIT) as a function of diagonal disorder, as well as its ene rgy dependence. Furthermore we investigate the different influence of odd a nd even system sizes on the localization properties in quasi one-dimensiona l systems. Applying the finite-size scaling approach in conjunction with a nonlinear fitting procedure yields the critical parameters of the MIT. In t hree dimensions, we find that the resulting critical exponent of the locali zation length agrees with the exponent for the Anderson model with pure dia gonal disorder.