Time-bin-encoding-based remote states generation of nitrogen-vacancy centers through noisy channels*
Su Shi-Leia), Chen Lib), Guo Qia), Wang Hong-Fuc), Zhu Ai-Dongc), Zhang Shoua),c)†
       
A schematic diagram to generalize W state generation to n -qubit case. The photon pulses are both prepared in | R ⟩ state and the NV centers are all prepared in |+⟩ state. H l denotes the HWP with the action and HWP k denotes the HWP with the action | R ⟩↔| L ⟩. (a) To generate n qubit W state between two nodes. The control sequences are the same as those in Fig. 3 . (b) To generate an n qubit W state among n nodes. The control sequences are the same as those in Fig. 6 . The optical path and elements from node 2 to node n – 1 are all the same, except for the delay lines (marked with green boxes) under the optical switches S9 k –9, whose length is designed as L D j = 2 j –1 L D.