Probing topological states through the exact non-Markovian decoherence dynamics of a spin coupled to a spin bath in the real-time domain

In this paper, we explore the decoherence dynamics of a probing spin coupled to a spin bath, where the spin bath is given by a controllable 1D transverse-field Ising chain. The 1D transverse-field Ising chain with free-end boundary condition is equivalent to a modified Kitaev model with nonlocal Majorana bound states in its topological phase. We find that the non-Markovian decoherence dynamics of the probing spin can manifest the topological structure of the spin chain. By controlling the external magnetic field on the Ising chain, we find a close relationship between the topological phase transition and the non-Markovian dynamics in the real-time domain. We also investigate the corresponding quantum entanglement dynamics in this topological system.