Effect of entanglement embedded in environment on quantum non-Markovianity based on collision model

Xiao-Ming Li(李晓明),Yong-Xu Chen(陈勇旭),Yun-Jie Xia(夏云杰),Zhong-Xiao Man(满忠晓)

Figure 4. Sketch of collision model Ⅱ. (a) Pairwise collisions (S-S1, S-S2) occur between system qubit and auxiliary qubits, hence they are correlated. (b) Auxiliary qubits S1 and S2 collide with the subancillas R11 and R12 in ancilla R1, respectively. The dotted blue lines in the graph denote the correlation among S1, S2 and S established after their collisions (i.e. after Step (a)). (c) The two subancillas in ancilla R1 collide with the two subancillas in ancilla R2, respectively. The dotted blue lines denote the correlation among S, S1, S2, R11 and R12 established after Step (b). (d) The ancilla R1 is traced out, and then the processes (a)–(c) are repeated.