(英) |
This study analyses the efficiency of three strategies to discriminate two Trace-Preserving Completely Positive maps (TPCP maps) by optimizing the input quantum query. The results are as follows. For N = 1, the efficiencies of all strategies degenerate. For N ≥ 2, the adaptive query strategy showed at least an exponential advantage compared to the parallel entangled query strategy by choosing the local operations as appropriate unitary operations. Therefore, this work is a natural generalization of the two unitary operator discrimination by an adaptive query in the past. The study also shows that the sharp discrimination using entanglement and a local TPCP map is impossible unless the target TPCP-maps are disjoint. However, the strategy would give an advantage over any other strategy thanks to the entanglement. |