Cold Atoms

Tapio Simula

Xinchuan Ouyang, Bowen Yang, Jianliao Deng +5 more

We propose a simple pumping method to increase the effective population of cold atoms in the clock state and investigate the factors which affect the pumping efficiency in cold atom systems. We report the theory and demonstrate the corresponding experiment in an 87Rb integrating sphere cold atom clock. The experimental results show that the population of cold atoms in the Zeeman sublevel |F = 2, mF = 0〉 is approximately 1.62 times that of the result using optical pumping alone. This method can also be applied to increase the effective population in any one of the target Zeeman sublevels in other cold atom systems.

Sixuan He, Dewei Wu, Qiang Miao

As the core sensors of inertial navigation, the accuracy of gyroscope and accelerometer directly determines the performance of inertial navigation system. With the appearance of cold atom interference technology, it has a wide application prospect in the field of inertial measurement, and cold atom gravimeter and cold atom gyroscope have appeared in succession. This paper mainly introduces the basic principle of cold atom interference technology, and briefly describes the development status of cold atom gyroscope and accelerometer. The existing problems in the current research is summarized, and its future application in navigation are prospected.

Yaning Wang, Yanling Meng, Jinyin Wan +5 more

An optical-plus-microwave pumping method is implemented and optimized to pump cold atoms to a magnetically insensitive state in an integrating sphere. This method consists of several optical and microwave pulses with a proper time sequence. The relative population of cold atoms in the Zeeman sublevel $|F=1,{m}_{F}=0\ensuremath{\rangle}$ is tested by measuring the Rabi oscillations and Ramsey fringes with different numbers of optical and microwave pumping pulses, demonstrating that nearly 83% of the cold atoms can be prepared in the clock state. The number of cold atoms in the target state is up to 2.5 times more than that of the optical pumping alone. Thus, the limitation on the stability of an integrating sphere cold-atom clock from atomic noise is estimated to be from $4.6\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}13}{\ensuremath{\tau}}^{\ensuremath{-}1/2}$ to $3.0\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}13}{\ensuremath{\tau}}^{\ensuremath{-}1/2}$. This method is also suitable for other precision measurements with cold atoms.