We investigate the phase sensitivity of the SU(1,1) interfereometer [SU(1,1)I] and the modified Mach-Zehnder in- terferometer (MMZI) with the entangled coherent states (ECS) as inputs. We consider the ideal ca...We investigate the phase sensitivity of the SU(1,1) interfereometer [SU(1,1)I] and the modified Mach-Zehnder in- terferometer (MMZI) with the entangled coherent states (ECS) as inputs. We consider the ideal case and the situations in which the photon losses are taken into account. We find that, under ideal conditions, the phase sensitivity of both the MMZI and the SU(1,1)I can beat the shot-noise limit (SNL) and approach the Heisenberg limit (HL). In the presence of photon losses, the ECS can beat the coherent and squeezed states as inputs in the SU(1,1)I, and the MMZI is more robust against internal photon losses than the SU(1,1)I.展开更多
基金supported by the Major Research Plan of the National Natural Science Foundation of China(Grant No.91121023)the National Natural Science Foundation of China(Grant Nos.11574092,61378012,and 60978009)+2 种基金the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20124407110009)the National Basic Research Program of China(Grant Nos.2011CBA00200 and 2013CB921804)the Program for Innovative Research Team in University(Grant No.IRT1243)
文摘We investigate the phase sensitivity of the SU(1,1) interfereometer [SU(1,1)I] and the modified Mach-Zehnder in- terferometer (MMZI) with the entangled coherent states (ECS) as inputs. We consider the ideal case and the situations in which the photon losses are taken into account. We find that, under ideal conditions, the phase sensitivity of both the MMZI and the SU(1,1)I can beat the shot-noise limit (SNL) and approach the Heisenberg limit (HL). In the presence of photon losses, the ECS can beat the coherent and squeezed states as inputs in the SU(1,1)I, and the MMZI is more robust against internal photon losses than the SU(1,1)I.