Absence of temporal order in states with fast decay of spatial correlations

Yichen Huang

Published 2019-12-03Version 1

In quantum lattice systems, we prove that any stationary state with sufficiently fast power-law (or even exponential) decay of spatial correlations has vanishing macroscopic temporal order in the thermodynamic limit. Assuming translational invariance, we obtain a similar bound on the temporal order between local operators at late times. Our proofs do not require any locality of the Hamiltonian. Applications in quantum time crystals are briefly discussed.