Z2 topological quench dynamics

We study a quantum quench protocol with Z2 topology in 3+1 dimensions. The Z2 feature is classified by the homotopy group Pi4(SU(2)) and the Z2 topological invariant is constructed from the dimensional reduction method. Furthermore, we show that the entanglement spectra can identify the Z2 signature. Finally, we discuss the possible realization in cold-atom systems and quantum optics.