title: Environmental coherence and excitation effects in non-Markovian dynamics.
abstract: We study the non-Markovian dynamics of a qubit system coupled respectively to coherent state, squeezing vacuum state, and mixed state environments through dephasing interaction. Special attention is paid to the problem of environmental coherence and excitation on the effect of non-Markovianity of system dynamics. Some nontrivial and unexpected results are found. The number of environmental excitations serves to enhance the non-Markovianity of system dynamics, but the enhancement slows down with the increasing of the variance of excitation number. However, environmental coherence can play dual effects, which enhances in some cases and suppresses in other cases the non-Markovianity of system dynamics.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Wen
authors.initials: W
authors.lastname: Cheng
authors.forename: Ze-Yu
authors.initials: ZY
authors.lastname: Gao
authors.forename: Hao-Sheng
authors.initials: HS
authors.lastname: Zeng