Characterizing correlations with full counting statistics: classical   Ising and quantum XY spin chains
  We propose to describe correlations in classical and quantum systems in terms of full counting statistics of a suitably chosen discrete observable. The method is illustrated with two exactly solvable examples: the classical one-dimensional Ising model and the quantum spin-1/2 XY chain. For the one-dimensional Ising model, our method results in a phase diagram with two phases distinguishable by the long-distance behavior of the Jordan-Wigner strings. For the quantum XY chain, the method reproduces the previously known phase diagram. 
Dmitri A. Ivanov, Alexander G. Abanov
cond-mat.str-el cond-mat.mes-hall cond-mat.stat-mech quant-ph