Coherent Population Trapping-Ramsey Interference in Cold Atoms

Min Xie, Guojian Yang

Zachary Warren

Chen Xi, Yang Guo-Qing, Wang Jin +1 more

We demonstrate an experimental observation of coherent population trapping-Ramsey interference in cold 87 Rb atoms by employing the time-domain separated oscillatory fields' method. The interference fringe with line width of 80Hz is obtained. We propose a novel method to measure the cold atom number. The measurement is insensitive to the pump beam intensity, the single photon detuning and even the initial state population. We use this method to normalize the interference signal and to improve the signal-to-noise ratio significantly.

G. S. Pati, Renu Tripathi, Gustavo Acosta +1 more

We are investigating coherent population trapping (CPT) and Ramsey-CPT interrogations in a cold atom system where the atomic beam originates from a pushed two-dimensional magneto-optical trap (2D+-MOT). Our results show promise for improving the performance of atomic clock using a cold atomic beam apparatus.

Chengyin Han, Bo Lü, Chaohong Lee

The utilization of Ramsey interferometry via coherent population trapping (CPT), which enables the optical interrogation of microwave transitions without the reliance on microwave cavities, plays a crucial role in the advancement of compact and low-power quantum sensors. Particularly, high-resolution CPT-Ramsey spectroscopy of alkali-metal atoms has found extensive application in constructing miniaturized quantum sensors like atomic magnetometers and atomic clocks. Due to their well-defined environment and extended coherence time, cold atoms offer enhanced sensitivity and precision in CPT-Ramsey interferometry. This review comprehensively examines CPT-Ramsey interferometry with cold atoms, encompassing both conventional and multi-pulse techniques, and explores their potential applications in practical quantum sensors.