Floquet dynamical phase transition and entanglement spectrum
R. Jafari, Alireza Akbari
Abstract
We explore both pure and mixed state Floquet dynamical quantum phase transitions (FDQFTs) in the one-dimensional $p$-wave superconductor with a time-driven pairing phase. In the Fourier space the model is recast to the noninteracting quasispins subjected to a time-dependent effective magnetic field. We show that FDQFTs occur within a range of driving frequency without resorting to any quenches. Moreover, FDQFTs appear in the region where quasispins are in the resonance regime. In the resonance regime, the population completely cycles the population between the spin down and up states. Additionally, we study the conditions for the appearance of FDQFTs using the entanglement spectrum and purity entanglement measure. Our results imply that the entanglement spectrum can truly capture the resonance regime where FDQFTs occur. Particularly, the dynamical topological region results in the degeneracy of the entanglement spectrum. It is shown that the boundary of the driven frequency range, over which the system reveals FDQFTs, is signaled by the purity entanglement measure.