Fragility of classical Hamiltonian period doubling to quantum fluctuations

We add quantum fluctuations to a classical period-doubling Hamiltonian time crystal, replacing the Nclassical interacting angular momenta with quantum spins of size l The full permutation symmetry of the Hamiltonian allows a mapping to a bosonic model and the application of exact diagonalization for a quite large system size. In the thermodynamic limit N\ensuremath{\rightarrow}\ensuremath{\infty}the model is described by a system of...