Crossed spin-1/2 Heisenberg chains as a quantum impurity problem
arXiv:cond-mat/0507312 · doi:10.1103/PhysRevLett.95.186404
Abstract
Using equivalencies between different models we reduce the model of two spin-1/2 Heisenberg chains crossed at one point to the model of free fermions. The spin-spin correlation function is calculated by summing the perturbation series in the interchain coupling. The result reveals a power law decay with a nonuniversal exponent.
3 pages, the background information is added