Constrained Dynamics and Directed Percolation.

In a recent work [A. Deger et al., Phys.

Arresting Classical Many-Body Chaos by Kinetic Constraints.

We investigate the effect of kinetic constraints on classical many-body chaos in a translationally invariant Heisenberg spin chain using a classical counterpart of the out-of-time-ordered correlator (OTOC). The strength of the constraint drives a "dynamical phase transition" separating a delocalized phase, where the classical OTOC propagates ballistically, from a localized phase, where the OTOC does not propagate at all and the entire system freezes. This is unexpected given that all spin configurations are dynamically connected to each other.

Lee-Yang zeros and large-deviation statistics of a molecular zipper.

The complex zeros of partition functions were originally investigated by Lee and Yang to explain the behavior of condensing gases. Since then, Lee-Yang zeros have become a powerful tool to describe phase transitions in interacting systems. Today, Lee-Yang zeros are no longer just a theoretical concept; they have been determined in recent experiments.