The metal-insulator transition on a random wire network

We have calculated the critical exponent of the metal-insulator transition for a three-dimensional network of random wires. The Hamiltonian of this model is not explicitly defined, and so we do not bias our results towards the models with diagonal or off-diagonal disorder, which produce conflicting exponents. The result is s= nu =1.10+or-0.05, which is in agreement with other models using tight-binding Hamiltonians with off-diagonal disorder. We suggest that pure wave interference is not the dominant mechanism for Hamiltonians with diagonal disorder and therefore some other physical process must be responsible for generating exponents of s= nu approximately=1.5.