Figure 1.

Schematic representation of a QNN_QG and RQNN_QG in an (n − 1)-th and r-th measurement rounds. The (n + 1)-length input systems of the (r − 1) and r-th measurement rounds are depicted by $|{\psi }_{r-1}\rangle |1\rangle$ and $|{\psi }_r\rangle |1\rangle$, the output systems are $|Y_{r-1}\rangle$ and $|Y_r\rangle$. The result of the M measurement operator in the (n − 1)-th and r-th measurement rounds are denoted by $Y_{n+1}^{\left(r-1\right)}$ and $Y_{n+1}^{\left(r\right)}$. (a) In a QNN_QG, for an r-th measurement round, side information is not available about the previous (n − 1)-th measurement round. (b) In a RQNN_QG, side information is available about the previous (n − 1)-th measurement round in an r-th round.