Compared with passive interferometers,SU(1,1)interferometers demonstrate superior phase sensitivity due to the incorporation of nonlinear elements that enhance their ability to detect phase shifts.Nevertheless,the mea...Compared with passive interferometers,SU(1,1)interferometers demonstrate superior phase sensitivity due to the incorporation of nonlinear elements that enhance their ability to detect phase shifts.Nevertheless,the measurement precision of these interferometers is considerably impacted by photon losses,particularly internal losses,thereby restricting the overall accuracy of measurements.Addressing these issues is essential to fully realize the advantages of SU(1,1)interferometers in practical applications.Among the available resources in quantum metrology,squeezing stands out as one of the most practical and efficient approaches.We propose a theoretical scheme to improve the precision of phase measurement using homodyne detection by implementing the single-path local squeezing operation(LSO)inside the SU(1,1)interferometer,with the coherent state and the vacuum state as the input states.We not only analyze the effects of the single-path LSO scheme on the phase sensitivity and the quantum Fisher information(QFI)under both ideal and photon-loss cases but also compare the impact of different squeezing parameters r on the system performance.Our findings reveal that the internal single-path LSO scheme can significantly enhance the phase sensitivity and QFI by strengthening intramode correlations while weakening intermode correlations,thereby effectively improving the robustness of the SU(1,1)interferometer against photon losses.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.11964013 and 12104195)the Jiangxi Provincial Natural Science Foundation(Grant Nos.20242BAB26009 and 20232BAB211033)+1 种基金Jiangxi Provincial Key Laboratory of Advanced Electronic Materials and Devices(Grant No.2024SSY03011)Jiangxi Civil-Military Integration Research Institute(Grant No.2024JXRH0Y07).
文摘Compared with passive interferometers,SU(1,1)interferometers demonstrate superior phase sensitivity due to the incorporation of nonlinear elements that enhance their ability to detect phase shifts.Nevertheless,the measurement precision of these interferometers is considerably impacted by photon losses,particularly internal losses,thereby restricting the overall accuracy of measurements.Addressing these issues is essential to fully realize the advantages of SU(1,1)interferometers in practical applications.Among the available resources in quantum metrology,squeezing stands out as one of the most practical and efficient approaches.We propose a theoretical scheme to improve the precision of phase measurement using homodyne detection by implementing the single-path local squeezing operation(LSO)inside the SU(1,1)interferometer,with the coherent state and the vacuum state as the input states.We not only analyze the effects of the single-path LSO scheme on the phase sensitivity and the quantum Fisher information(QFI)under both ideal and photon-loss cases but also compare the impact of different squeezing parameters r on the system performance.Our findings reveal that the internal single-path LSO scheme can significantly enhance the phase sensitivity and QFI by strengthening intramode correlations while weakening intermode correlations,thereby effectively improving the robustness of the SU(1,1)interferometer against photon losses.
