Non-Markovian Speedup Dynamics in Markovian and Non-Markovian Channels

We have studied the behavior of the open-system dynamics of a spin-qubit subject to the competing actions of Markovian and non-Markovian environments. We theoretically study the dynamics crossovers from Markovian to non-Markovian and from no-speedup to speedup. We find that the energy mismatch between the open-system and non-Markovian environments play a significant role in dynamics transitions. And the transition can be realized by controlling the number of outer spins and the coupling strength with two kinds of decoherence channels, the increase of the number of decoherence channels have the effect on increasing the amount of non-Markovianity and speeding-up evolution of the spin-qubit.