title: Loschmidt Echo Revivals: Critical and Noncritical.
abstract: A quantum phase transition is generally thought to imprint distinctive characteristics on the nonequilibrium dynamics of a closed quantum system. Specifically, the Loschmidt echo after a sudden quench to a quantum critical point-measuring the time dependence of the overlap between initial and time-evolved states-is expected to exhibit an accelerated relaxation followed by periodic revivals. We here introduce a new exactly solvable model, the extended Su-Schrieffer-Heeger model, the Loschmidt echo of which provides a counterexample. A parallell analysis of the quench dynamics of the three-site spin-interacting XY model allows us to pinpoint the conditions under which a periodic Loschmidt revival actually appears.
authors.affiliation: Beijing Computational Science Research Center, Beijing 100094, China.|Department of Physics, University of Gothenburg, SE 412 96 Gothenburg, Sweden.|Department of Physics, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran.
authors.forename: R
authors.initials: R
authors.lastname: Jafari
authors.affiliation: Beijing Computational Science Research Center, Beijing 100094, China.|Department of Physics, University of Gothenburg, SE 412 96 Gothenburg, Sweden.
authors.forename: Henrik
authors.initials: H
authors.lastname: Johannesson