We demonstrate the inadequacy of mean-field theory by exploring the effects of initial state correlations on the dynamics of continuous time crystals, necessitating higher-order cumulant expansions. We exemplify this using cat states for which the mean field fails to predict a phase transition but the second order cumulant expansion theory captures it. Motivated by the symmetries of the system, we choose a truncation of cumulant theory at the second-order and demonstrate that it is sufficient to accurately capture the dynamical features overlooked by the mean-field.
@article{arxiv.2403.15164,
title = {Symmetries & Correlations in Continous Time Crystals},
author = {Ankan Mukherjee and Yeshma Ibrahim and Michal Hajdušek and Sai Vinjanampathy},
journal= {arXiv preprint arXiv:2403.15164},
year = {2025}
}