Fractonic Quantum Quench in Dipole-constrained Bosons

We investigate the quench dynamics in the dipolar Bose-Hubbard model (DBHM) in one dimension where the boson hopping is constrained by dipole conservation and show fractonic dynamics. Quench processes that start deep in the Mott phase and end in the weak Mott phase show light-cone-like spreading in the dipole correlation function but not in the single-boson correlator, which is suppressed due to the dipole conservation. The phase and the group velocities estimated from the dilute-dipolon approximation are in excellent agreement with those of exact numerical diagonalization. The quench from dipoled-condensed (DC) phase to the Mott phase shows periodic kinks in the Loschmidt echo and the demise and revival of Bose-condensed peaks in the dipole momentum distribution function, both of which are noted features of dynamical quantum phase transition. The Mott-to-DC quench, on the other hand, shows none of these features despite the quench parameters varying across the equilibrium quantum critical point. Our findings on the fractonic quench dynamics can be checked in the tilted optical lattice experiment.