Laser Cooling and Magnetic Trapping at Several Tesla

Abstract

Laser cooling and magnetic trapping of (85)Rb atoms have been performed in extremely strong and tunable magnetic fields, extending these techniques to a new regime and setting the stage for a variety of cold atom and plasma experiments. Using a superconducting Ioffe-Pritchard trap and an optical molasses, 2.4 x 10(7) atoms were laser cooled to the Doppler limit and magnetically trapped at bias fields up to 2.9 T. At magnetic fields up to 6 T, 3 x 10(6) cold atoms were laser cooled in a pulsed loading scheme. These bias fields are well beyond an order of magnitude larger than those in previous experiments. Loading rates, molasses lifetimes, magnetic-trapping times, and temperatures were measured using photoionization and electron detection.

Review of cold Rydberg atoms and their applications

“…The effects of magnetic fields on Rydberg atoms are highlighted by the presence of quasi-Landau resonances above the ionization limit which shows a series of sharp resonances at frequency intervals of 3ω c /2, where ω c = eB/mc is the electron cyclotron frequency [48]. Recently, magnetic trapping of cold Rydberg atoms has revealed collective oscillations of cold atoms, showing extremely long Rydberg gas lifetimes of up to 200 ms [49,50].…”

Evolution dynamics of a dense frozen Rydberg gas to plasma

“…Such a plasma can be created by photoionization of atoms in a magneto-optical trap (MOT) using a pulsed laser. The initial observation of this phenomenon was made using 50 K Xe atoms, but since then similar results have been found using cold Rb, Cs, and Sr atoms [2][3][4][5]. To a very good approximation, the initial electron energy is determined by the excess photon energy above the ionization limit of the photoionizing laser, while the initial positive ion temperature is that of the initially trapped atoms before ionization.…”

Green-function method in the theory of ultraslow electromagnetic waves in an ideal gas with Bose-Einstein condensates

“…Then, on the basis of Eqs. (27) and (35), one may get the following region where the slowing phenomenon may be observed:…”

“…(24)) because of the fact that in the cases studied below it is rather small in comparison with the characteristic quantities that give the leading contribution to the slowing phenomenon. The expression (27) can be written also in the more usual form (cf. Refs.…”

“…For example, to reduce the clock transition wavelength to λ hf = 2 mm in cesium, the field intensity must be of the order of 45 kG, which is quite achievable from the standpoint of the trapping-related experiments (see Ref. [27]). Let us note also that, corresponding to the results [6] (see also Fig.…”