Preparation of a high concentration of lithium-7 atoms in a magneto-optical trap

Abstract

This study is aimed at obtaining high concentration of optically cooled lithium 7 atoms for pre paring strongly interacting ultracold plasma and Rydberg matter. A special setup has been constructed, in which two high power semiconductor lasers are used to cool lithium 7 atoms in a magneto optical trap. At an optimum detuning of the cooling laser frequency and a magnetic field gradient of 35 G/cm, the concentra tion of ultracold lithium 7 atoms reaches about 10 11 cm -3 . Additional independent information about the concentration and number of ultracold lithium 7 atoms on different sublevels of the ground state was obtained by using of an additional probing laser.

Observation of Rydberg Transitions in Resonance Fluorescence of Ultracold Lithium-7 Atoms

“…The estimated temperature of the trapped atoms is of the order of 5 · 10 −4 K. The concentration n and total number N of atoms can be enhanced by increasing the magnetic field gradient. The linear dependence of n and N on the magnetic field gradient in the range 20 -35 Gauss/cm has been observed earlier [14].…”

Quantum defects in RydbergnD states of optically cooled7Li atoms

“…To cool and trap the 7 Li atoms after the Zeeman slower we used two cooling diode lasers with fixed frequencies ν c and ν op : the main cooling laser and the re-pumping laser. Parameters of our MOT are described in [3,[12][13][14]. In our experiment the intensities of the laser cooling beams inside the vacuum chamber were 0.04 and 0.02 W cm −2 .…”