The Dynamical Topological Phase Transitions in a Quenched Kitaev Model

Li-Na Luan, Shuai Liu, Zhi-Xu Zhang

S.R. Ghazanfari, Hosein Mokhtari

Qi Chen, Guo-Qing Zhang, Jun-Qing Cheng +1 more

Guang-Ming Zhang

Leela Ganesh Chandra Lakkaraju, Sudip Kumar Haldar, Aditi Sen

An exactly solvable Kitaev model in a two-dimensional square lattice exhibits a topological quantum phase transition which is different from the symmetry-breaking transition at zero temperature. When the ground state of a nonlinearly perturbed Kitaev model with different strengths of perturbation taken as the initial state is quenched to a pure Kitaev model, we demonstrate that various features of the dynamical state, such as the Loschmidt echo and time-averaged multipartite entanglement, can determine whether the initial state belongs to the topological phase or not. Moreover, the derivatives of the dynamical quantifiers can faithfully identify the topological quantum phase transition, which is present at equilibrium. When the individual qubits of the lattice interact with the local thermal bath repeatedly, we observe that block entanglement in dissipative dynamics can, nevertheless, distinguish the equilibrium phases from which the system starts evolution.

Kaixiang Su, Zheng‐Hang Sun, Heng Fan

We study the quench dynamics of entanglement spectra in the Kitaev chain with variable-range pairing quantified by power-law decay rate $\ensuremath{\alpha}$. Considering the post-quench Hamiltonians with flat bands, we demonstrate that the presence of entanglement-spectrum crossings during its dynamics is able to characterize the topological phase transitions (TPTs) in both short-range ($\ensuremath{\alpha}>1$) and long-range ($\ensuremath{\alpha}<1$) sectors. Properties of entanglement-spectrum dynamics are revealed for the quench protocols in the long-range sector or with $\ensuremath{\alpha}$ as the quench parameter. In particular, when the lowest upper-half entanglement-spectrum value of the initial Hamiltonian is smaller than the final one, the TPTs can also be diagnosed by the difference between the lowest two upper-half entanglement-spectrum values if the halfway winding number is not equal to that of the initial Hamiltonian. Moreover, we discuss the stability of characterizing the TPTs via entanglement-spectrum crossings against energy dispersion in the long-range model.