Universal scaling dynamics of a many-body system far from equilibrium signals the proximity of the time-evolution to a non-thermal fixed point. We find universal dynamics connected with rogue-wave like events in the mutually coupled magnetic components of a spinor gas which propagate in an effectively random potential. The frequency of these caustics is affected by the time varying spatial correlation length of the potential, giving rise to an additional exponent δc≃1/3 for temporal scaling, which is different by a factor ∼4/3 from the exponent βV≃1/4 characterizing the scaling of the correlation length ℓV∼t βV with time. As a result of the caustics, real-time instanton defects appear in the Larmor phase of the spin-1 system as vortices in space and time. The temporal correlations determining the frequency of instanton events to occur scale in time as t δI. This suggests that the universality class of a non-thermal fixed point could be characterized by different, mutually related exponents defining the coarsening evolution in time and space, respectively. Our results have a strong relevance for understanding pattern coarsening from first principles and potential implications for dynamics ranging from the early universe to geophysical dynamics and micro physics.

I. Siovitz, S. Lannig, Y. Deller, H. Strobel, M.K. Oberthaler, T. Gasenzer, “Universal dynamics of rogue waves in a quenched spinor Bose condensate”, arXiv:2304.09293 (2023).


Related to Project A04