Critical exponent of dynamical quantum phase transitions in the one-dimensional Bose-Hubbard model in the strongly interacting limit
Phys. Rev. A 112, 063307 – Published 10 December, 2025
DOI: https://doi.org/10.1103/rwln-wbs1
Abstract
We analytically investigated the dynamical quantum phase transitions in the Bose-Hubbard model using the Loschmidt echo as an observable, revealing that after a quench, the global Loschmidt echo exhibits cusp singularities with a logarithmically divergent rate function near criticality and a critical exponent of zero. Through extensive calculations across various system sizes and initial states, we have demonstrated that in the strongly interacting regime, the critical singularity of dynamical quantum phase transitions exhibits consistency across different model details and initial product states (charge-density wave states). Moreover, we find that modifying the harmonic potential well not only preserves the phase transition but also enables precise control over the transition timing.
