Dynamics of the modified Kibble-\.Zurek mechanism in antiferromagnetic spin-1 condensates

We investigate the dynamics and outcome of a quantum phase transition from an antiferromagnetic to phase separated ground state in a spin-1 Bose-Einstein condensate of ultracold atoms. We explicitly demonstrate double universality in dynamics within experiments with various quench time. Furthermore, we show that spin domains created in the nonequilibrium transition constitute a set of mutually incoherent quasicondensates. The quasicondensates appear to be positioned in a semi-regular fashion, which is a result of the conservation of local magnetization during the post-selection dynamics.