LIU Xian-feng1, HAN Jiu-rong1, ZHANG Shou-gang2,3

(1. College of Physics Science and Technology, Yangzhou University, Yangzhou 225002, China;

2. National Time Service Center, Chinese Academy of Sciences, Xi’an 710600, China;

3. Key Laboratory of Time and Frequency Primary Standards, Chinese Academy of Sciences, Xi’an 710600, China) 

Abstract: The Ramsey’s method of separated oscillatory fields is applied to study Ramsey interferometry but using a Tonks-Girardeau model that describes a coherent one-dimensional gas of ultracold bosons with strong interactions. Under the equal detuning, the interference fringes width can be narrowed by increasing the Rabi frequency and the field-crossing time. Moreover, we gain further insight into the quantum projection noise.In contrast to a two-level TG gas, our results illustrate that the modulation of the total number of three-level atomsand the external fields tend to lower the quantum noise limit, so as to reduce the interference of the noise to the strongly interacting bosonic Tonks-Girardeau gas. The investigation on the atomic interferometry is a great theoretical guidance to the research of quantum frequency standard.

Key words:Tonks-Girardeau gas; Ramsey interferometry; quantum projection noise