Optimal phase sensitivity of atomic Ramsey interferometers with coherent spin states

作     者：Guang-ri JIN Yong-chun LIU Li YOU 

作者机构：Department of Physics Beijing Jiaotong University Beijing 100044 China Department of Physics Tsinghua University Beijing 100085 China 

出 版 物：《Frontiers of physics》 (物理学前沿（英文版）)

年 卷 期：2011年第6卷第3期

页      面：251-257页

核心收录：

学科分类：070207[理学-光学] 07[理学] 08[工学] 080401[工学-精密仪器及机械] 0804[工学-仪器科学与技术] 0803[工学-光学工程] 081102[工学-检测技术与自动化装置] 0811[工学-控制科学与工程] 0702[理学-物理学] 

基　　金：国家自然科学基金 国家教育部高等学校博士学科点专项科研基金 国家973计划 

主　　题：Ramsey interferometry phase estimation Bose-Einstein condensates phase decay,one-axis twisting model 

摘      要：We present a detailed analysis of phase sensitivity for a nonlinear Ramsey interferometer, which utilize effective mean-field interaction of a two-component Bose-Einstein condensate in phase ac- cumulation. For large enough particle number N and small phase shift φ, analytical results of the Ramsey signal and the phase sensitivity are derived for a product coherent state θ, 0）. When collisional dephasing is absent, we confirm that the optimal sensitivity scales as 2/N3/2 for polar angle of the initial state θ = π/4 or 3π/4. The best-sensitivity phase satisfies different transcendental equations, depending upon the initial state and the observable being measured after the phase accumulation. In the presence of the collisional dephasing, we show that the N-3/2-scaling rule of the sensitivity maintains with spin operators jx and jy measurements. A slightly better sensitivity is attainable for optimal coherent state with θ = π/6 or 5π/6.