Abstract

Co-authors: Pietro Smacchia (Rutgers), Eugene Demler (Harvard), Michael Knap (Munich), Anna Maraga (SISSA)

Dynamical phase transitions can occur in isolated quantum systems that are brought out of equilibrium by either a sudden or a gradual change of their parameters. Theoretical examples range from the behaviour of the O(N) model as well as spin-models with long range interactions both showing dynamical criticality in their prethermal steady-states. In this talk I will start by discussing the characterization of such dynamical phase transitions based on the statistics of produced excitations. I will also discuss the role of fluctuations as well as on the differences between sudden and gradual changes of the system parameters. Finally, I will discuss the emergence of zeroes in the Loschmidt amplitude attempting to elucidate their physical meaning in connection with the dynamical transitions above.