Differential two-photon spectroscopy for nondestructive temperature measurements of cold trapped atoms

In our talk various methods of temperature measurement of cold trapped atoms will be compared and discussed. We suggested a differential two-photon spectroscopic technique for nondestructive measurement of atomic temperature... [ view full abstract ]

In our talk various methods of temperature measurement of cold trapped atoms will be compared and discussed. We suggested a differential two-photon spectroscopic technique for nondestructive measurement of atomic temperature in magneto-optical and dipole traps. As example we performed experiments with cold ⁷Li atoms in the working magneto-optical trap. The two-photon resonances on Rydberg transitions 2S_1/2–2P_3/2–58S in cold ⁷Li atoms were studied by using counter and co-propagating probe laser beams. By analyzing the spectral shapes a dependence of Rabi broadening and Doppler broadening on intensity of cooling laser beams was obtained. We measured the temperature of ⁷Li atoms in the range from 0.25 to 0.75 mK. Our theoretical and experimental results are in a good agreement. The developed approach for temperature measurements can be applied to cold atoms in different traps, including confined hydrogen and antihydrogen atoms.

This work was supported by the Russian Science Foundation under Project No. 18-12-00424.