Entanglement in quenched extended Su-Schrieffer-Heeger model with anomalous dynamical quantum phase transitions

Dynamical Quantum Phase Transition (DQPT) aims to understand out-of-equilibrium physics. It was initially believed that quenching across the equilibrium boundary was a sufficient condition for DQPT, yet later findings show that it is not true, which are often referred to as "accidentals". In this work, we study the extended Su-Schrieffer-Heeger model and formulate the notion of type-B anomalous DQPT, defined as the number of critical momenta larger than the absolute difference between the final and initial phase winding numbers. This definition integrates the accidental DQPTs and an unusual type of DQPT into a single framework. We demonstrate that type-B anomalous and regular DQPTs are fundamentally different. The additional critical momenta in anomalous DQPT are complex conjugate pairs. Eigenvalues of the correlation matrix evolve toward the Fermi level more frequently in type-B anomalous than in regular DQPTs. By categorising phases into different classes according to their non-locality, generic extremum property of the entanglement entropy (EE) distinguishing type-B and regular DQPTs are also identified - regular DQPT occurs at the second or third local minima, while type-B anomalous DQPT occurs in the vicinity of the first local minima of EE.