Universal low-temperature properties of quantum and classical   ferromagnetic chains
  We identify the critical theory controlling the universal, low temperature, macroscopic properties of both quantum and classical ferromagnetic chains. The theory is the quantum mechanics of a single rotor. The mapping leads to an efficient method for computing scaling functions to high accuracy. 
Minoru Takahashi, Hiroaki Nakamura (Institute for Solid State Physics,   University of Tokyo) and Subir Sachdev (Department ...