Arresting classical many-body chaos by kinetic constraints

Understand

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 delocalised phase, where the classical OTOC propagates ballistically, from a localised phase, where the OTOC does not propagate at all and the entire system freezes.
• This is unexpected given that all spins configurations are dynamically connected to each other.
• We show that localisation arises due to the dynamical formation of frozen islands, contiguous segments of spins immobile due to the constraints, dominating over the melting of such islands.