Mercredi 30 mai 2012 à 11h15
Salle 234, Ecole de Physique

Phase transitions in full counting statistics

Dmitri Ivanov, ETH Zürich

We propose to describe correlations in classical and quantum systems in terms of full counting statistics (FCS) of a suitably chosen discrete observable. Thermodynamic phases may be characterized by analytical properties of the extensive part of the FCS. We illustrate our proposal with three examples: the classical Ising chain, the spin-1/2 XY chain, and free fermions in one dimension. In the last example, we find an asymptotic expansion for the FCS, which generalizes the Fisher-Hartwig conjecture for Toeplitz determinants.