title: Dynamical quantum phase transitions in the transverse-field Ising model.
abstract: A phase transition indicates a sudden change in the properties of a large system. For temperature-driven phase transitions this is related to nonanalytic behavior of the free energy density at the critical temperature: The knowledge of the free energy density in one phase is insufficient to predict the properties of the other phase. In this Letter we show that a close analogue of this behavior can occur in the real time evolution of quantum systems, namely nonanalytic behavior at a critical time. We denote such behavior a dynamical phase transition and explore its properties in the transverse-field Ising model. Specifically, we show that the equilibrium quantum phase transition and the dynamical phase transition in this model are intimately related.
authors.affiliation: Department of Physics, Arnold Sommerfeld Center for Theoretical Physics, Ludwig-Maximilians-Universität München, Theresienstrasse 37, 80333 Munich, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Heyl
authors.forename: A
authors.initials: A
authors.lastname: Polkovnikov
authors.forename: S
authors.initials: S
authors.lastname: Kehrein