We consider the nonequilibrium dynamics in quantum field theories (QFTs). After being prepared in a density matrix that is not an eigenstate of the Hamiltonian, such systems are expected to relax locally to a stationary state. In the presence of local conservation laws, these stationary states are believed to be described by appropriate generalized Gibbs ensembles. Here we demonstrate that in order to obtain a correct description of the stationary state, it is necessary to take into account conservation laws that are not (ultra) local in the usual sense of QFTs, but fulfill a significantly weaker form of locality. We discuss the implications of our results for integrable QFTs in one spatial dimension.
|Titolo:||Generalized Gibbs Ensembles for Quantum Field Theories|
|Autori:||Essler, F.H.L; Mussardo, G; Panfil, M.|
|Rivista:||PHYSICAL REVIEW A|
|Data di pubblicazione:||2015|
|Digital Object Identifier (DOI):||10.1103/PhysRevA.91.051602|
|Appare nelle tipologie:||1.1 Journal article|