摘要
在基于干涉仪的量子精密测量中,输入量子态的选择直接决定了待测相位的测量精度.本文考虑了基于压缩热态(特别是自由热态的情况)和Fock态的直积态作为马赫-曾德尔干涉仪的输入态,计算得到了宇称测量信号的解析解,进而得到了相位测量精度.研究结果表明:在待测相位很小时,压缩热态、压缩真空态以及自由热态与Fock态的直积态做为干涉仪的输入态时,均可得到相同的相位测量精度极限,且该测量极限达到了基于量子Fisher信息量子CrámerRao界限,所以宇称测量是相应的最优测量.同时,研究结果也表明,除了相干态,高强度的自由热态在量子精密测量中也有着一定的应用价值.
In quantum precision based optical interferometer, the phase sensitivity crucially depends on the nature of the quantum state. We analytically prove when a Mach-Zehnder interferometer powered by a Fock state into one input port, a thermal state, a squeezed vacuum state or a squeezed thermal state with same average photon number at the other input, the same performances in the phase estimation via parity detection can be obtained for small phase shift. We analytically prove that the parity detection saturates the quantum Cramér-Rao bound. In addition, our results show that besides a coherent state, a thermal state is another useful high-intensity classical state for the phase estimation.
作者
王帅
吴世臣
眭永兴
WANG Shuai;WU Shi-chen;SUI Yong-xing(School of Mathematics and Physics,Jiangsu University ofTechnology,Changzhou 213001,China)
出处
《聊城大学学报（自然科学版）》
2018年第4期77-82,110,共7页
Journal of Liaocheng University:Natural Science Edition
基金
国家自然科学基金项目(11404040)
江苏省自然科学基金项目(BK20140253)资助
