Quasi-periodic dynamical phase transitions in multi-band topological insulators

Nicholas Sedlmayr

Kaiyuan Cao, Hao Guo, Guangwen Yang

We investigate the dynamical quantum phase transition (DQPT) in the multi-band Bloch Hamiltonian of the one-dimensional periodic Kitaev model, focusing on quenches from a Bloch band. By analyzing the dynamical free energy and Pancharatnam geometric phase (PGP), we show that the critical times of DQPTs deviate from periodic spacing due to the multi-band effect, contrasting with results from two-band models. We propose a geometric interpretation to explain this non-uniform spacing. Additionally, we clarify the conditions needed for DQPT occurrence in the multi-band Bloch Hamiltonian, highlighting that a DQPT only arises when the quench from the Bloch states collapses the band gap at the critical point. Moreover, we establish that the dynamical topological order parameter, defined by the winding number of the PGP, is not quantized but still exhibits discontinuous jumps at DQPT critical times due to periodic modulation. Additionally, we extend our analysis to mixed-state DQPT and find its absence at non-zero temperatures.

Yanchao Li

Tomasz Masłowski, Nicholas Sedlmayr

Dynamical quantum phase transitions occur in dynamically evolving quantum systems when nonanalyticities occur at critical times in the return rate, a dynamical analog of the free energy. This extension of the concept of phase transitions can be brought into contact with another, namely, that of topological phase transitions in which the phase transition is marked by a change in a topological invariant. Following a quantum quench dynamical quantum phase transitions can happen in topological matter, a fact which has already been explored in one-dimensional topological insulators and in two-dimensional Chern insulators. Additionally, in one-dimensional systems a dynamical bulk boundary correspondence has been seen, related to the periodic appearance of zero modes of the Loschmidt echo itself. Here we extend both of these concepts to two-dimensional higher-order topological matter in which the topologically protected boundary modes are corner modes. We consider a minimal model which encompasses all possible forms of higher-order topology in two-dimensional topological band structures. We find that dynamical quantum phase transitions can still occur, and can occur for quenches which cross both bulk and boundary gap closings. Furthermore, a dynamical bulk boundary correspondence is also found, which takes a different form to that in one dimension.

Yifei Liu, Léa Ferreira dos Santos, Emil V. Prodan

J. R. Wen

Topological state characterization in interacting quasi-periodic systems remains challenging because conventional band-topology approaches become invalid in the presence of strong many-body correlations and broken translational symmetry. This study develops a generalized many-body Zak phase framework for investigating topological phase transitions in Bose–Einstein condensates confined within quasi-periodic potential wells. By introducing a quasimomentum manifold derived from quasi-periodic phase symmetry and constructing gauge-continuous ground-state families, topological invariants are directly extracted from many-body wavefunctions without relying on Bloch bands, Brillouin zones, or bulk energy gaps. The proposed approach is integrated with density matrix renormalization group calculations to establish a unified characterization of superfluid, localized, and critical regimes. Results show that a stable topologically nontrivial phase emerges at U/J = 3.2 and ∆/J = 2.8, where the momentum distribution exhibits symmetric peaks at k = ±π/2 with an amplitude of 1.87. Open-boundary analysis reveals strongly localized edge modes with approximately 90% density concentration near system boundaries, while the entanglement spectrum displays a symmetry-protected doubly degenerate structure. The results demonstrate that interaction and quasi-periodicity jointly stabilize nontrivial topological states and associated wave-localization phenomena. The proposed framework provides a rigorous methodology for analyzing topological phase evolution, geometric-phase transitions, and wave propagation characteristics in strongly correlated quasi-periodic systems.