title: Relaxation of antiferromagnetic order in spin-1/2 chains following a quantum quench.
abstract: We study the unitary time evolution of antiferromagnetic order in anisotropic Heisenberg chains that are initially prepared in a pure quantum state far from equilibrium. Our analysis indicates that the antiferromagnetic order imprinted in the initial state vanishes exponentially. Depending on the anisotropy parameter, oscillatory or nonoscillatory relaxation dynamics is observed. Furthermore, the corresponding relaxation time exhibits a minimum at the critical point, in contrast to the usual notion of critical slowing down, from which a maximum is expected.
authors.affiliation: Department of Physics, University of Fribourg, CH-1700 Fribourg, Switzerland.
authors.forename: Peter
authors.initials: P
authors.lastname: Barmettler
authors.forename: Matthias
authors.initials: M
authors.lastname: Punk
authors.forename: Vladimir
authors.initials: V
authors.lastname: Gritsev
authors.forename: Eugene
authors.initials: E
authors.lastname: Demler
authors.forename: Ehud
authors.initials: E
authors.lastname: Altman