Cutoff corrections to Gaussian-Heisenberg crossover behaviour
Ian D. Lawrie
The crossover behaviour between Gaussian and Heisenberg critical behaviour is studied in an isotropic n-vector model, in which the effect of a lattice cutoff, a= Lambda -1 , is imitated by means of (nabla 2 phi ) 2 and (nabla nabla 2 phi ) 2 terms in the effective Hamiltonian. A field theoretic method is used to construct, to first order in in =4-d, a crossover scaling function for the susceptibility containing the corrections to scaling which involve Lambda directly. The leading corrections vanish, near the Heisenberg fixed point, as ((T-T c ) v / Lambda ) 2 where v is the corresponding correlation length exponent, and near the Gaussian fixed point as ((T-T c ) 1 2// Lambda ) 2 .
Journal of Physics A Mathematical and General•Sep 1, 1977•9 citations