Dynamical detection of meanfield topological phases in an interacting Chern insulator
Abstract
Interactions generically have important effects on the topological quantum phases. For a quantum anomalous Hall (QAH) insulator, the presence of interactions can qualitatively change the topological phase diagram which, however, is typically hard to measure in the experiment. Here we propose a novel scheme based on quench dynamics to detect the meanfield topological phase diagram of an interacting Chern insulator, with nontrivial dynamical quantum physics being uncovered. We focus on a twodimensional QAH system in the presence of a weak to intermediate Hubbard interaction which only drives a magnetic order under the meanfield level. After quenching the Zeeman coupling, both the meanfield Hamiltonian and manybody quantum state evolve over time. This is in sharp contrast to quenching a noninteracting system, in which only the manybody state evolves. We find two characteristic times $t_s$ and $t_c$ which capture the emergence of dynamical selfconsistent particle number density and dynamical topological phase transition for the timedependent Hamiltonian, respectively. An interesting result is that $t_s>t_c$ ($t_s<t_c$) occurs in repulsive (attractive) interaction when the system is quenched from an initial fully polarized state to the topologically nontrivial regimes, and $t_s=t_c$ characterizes the topological phase boundaries. Moreover, the topological number of meanfield topological phase is determined by the spin polarizations of four Dirac points at the time $t_s$. With these results we provide a feasible scheme to detect the meanfield topological phase diagram via the two characteristic times in quench dynamics, which can reveal the novel interacting effects on the topological phases and shall promote the experimental observation.
 Publication:

arXiv eprints
 Pub Date:
 June 2022
 arXiv:
 arXiv:2206.11018
 Bibcode:
 2022arXiv220611018J
 Keywords:

 Condensed Matter  Strongly Correlated Electrons;
 Condensed Matter  Mesoscale and Nanoscale Physics;
 Condensed Matter  Quantum Gases;
 Quantum Physics
 EPrint:
 12 pages, 6 figures.References are updated