We investigate phase estimation in a lossy interferometer using entangled coherent states,with a particular focus on a scenario where no reference beam is employed.By calculating the quantum Fisher information,we reve...We investigate phase estimation in a lossy interferometer using entangled coherent states,with a particular focus on a scenario where no reference beam is employed.By calculating the quantum Fisher information,we reveal two key results:(1)the metrological equivalence between scenarios with and without a reference beam,established under ideal lossless conditions for the two-phase-shifting configuration,breaks down in the presence of photon loss,and(2)the pronounced inferior performance of ECSs relative to NOON states,observed in the presence of a reference beam,disappears in its absence.展开更多
基金supported by the NSFC through Grant No.12005106the Postgraduate Research and Practice Innovation Program of Jiangsu Province(Grant No.JSCX23-0260)Natural Science Foundation of Nanjing University of Posts and Telecommunications(Grant No.NY224127)。
文摘We investigate phase estimation in a lossy interferometer using entangled coherent states,with a particular focus on a scenario where no reference beam is employed.By calculating the quantum Fisher information,we reveal two key results:(1)the metrological equivalence between scenarios with and without a reference beam,established under ideal lossless conditions for the two-phase-shifting configuration,breaks down in the presence of photon loss,and(2)the pronounced inferior performance of ECSs relative to NOON states,observed in the presence of a reference beam,disappears in its absence.
