Regensburg 2025 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

DY: Fachverband Dynamik und Statistische Physik

DY 31: Focus Session: Nonequilibrium Collective Behavior in Open Classical and Quantum Systems

DY 31.9: Vortrag

Donnerstag, 20. März 2025, 12:00–12:15, H37

Universality in time-crystalline matter — •Carl Philipp Zelle, Romain Daviet, Achim Rosch, and Sebastian Diehl — University of Cologne

Dynamical phases of matter in which time translation symmetry is broken spontaneously are fascinating examples of phases that can only occur far from equilibrium. In this talk, we show that paradigmatic O(N) models display time-crystalline order once driven suitably out of equilibrium.

We employ dynamic RG techniques to determine the universal phenomena at the ensuing transitions as well as within the time-crystalline phase: The transition between an ordered phase and the time-crystal occurs through a critical exceptional point which we show cause a fluctuation-induced first order transition. The transition between a symmetric and a time-crystalline phase defines a new, genuinely nonthermal universality class. We show, that the Goldstone-modes within the dynamical phases are a realisation of the KPZ universality class and offer new generalisations of KPZ to larger symmetry groups.

Surprisingly, these phenomena can be realized by rather simple driving protocols, i.e. weakly irradiating a ferrimagnetic spin system. Furthermore, we connect our results to recent advances in nonreciprocal active matter.

Based on

1) Zelle, Daviet, Rosch, Diehl; Phys. Rev. X 14, 021052 (2024)

2) Daviet, Zelle, Rosch, Diehl; Phys. Rev. Lett. 132, 167102 (2024)

3) Zelle, Daviet, Asadollahi, Diehl; in preparation

Keywords: Nonequilibrium Universality; Time Crystals; Driven Magnets; Active Matter