Localized atomic vortices and periodic atomic clustering in a deep 3D optical superlattice

Gabriela Wa̧sik, Rudolf Grimm

I. V. Krasnov

I. V. Krasnov

Abstract A novel mechanism of the formation of a deep optical superlattice (OSL) for three-dimensional (3D) trapping of resonant impurity atoms immersed in a transparent cold buffer gas is proposed and investigated theoretically. This mechanism is associated with the joint action of two factors of different physical nature: rectification effect of the gradient force of light pressure and effect of the light induced drift (LID) of atoms (a consequence of the difference in gas-kinetic cross sections of excited and unexcited atoms). Such a situation can be realised when a gas mixture is irradiated by a bichromatic combined light beam which is a special coaxial superposition of cosine-Gaussian optical beams. Here, the RcGF creates a periodic 1D array of deep potential wells (OSL) along the beam axes, and an effective force, causing LID, pulls resonant particles into the combined light beam and provides their transverse (with respect to the beam axes) confinement in OSL. As a result, there can occur a giant accumulation of impurity particles in the OSL cells, accompanied by a strong spatial particle localization far away from the walls of the reservoir, in which the gas mixture is located.

I. V. Krasnov

Abstract We consider a novel deep three-dimensional (3D) optical superlattice (OSL) for the trapping and long-term 3D confinement of resonant impurity atoms immersed in a cold buffer gas. This OSL provides reliable isolation of the atoms from the vessel walls containing the gas mixture. Its operating principle is based on utilizing nonlinear interference phenomena within the light-induced drift effect and effective rectified forces arising from the interaction of an atom with a non-monochromatic light field. This concept was previously proposed and analyzed (for the case of a bichromatic field) in our prior work Krasnov (2024 Laser Phys. Lett. 21 095501) using a simple scalar (two-level) atom-field interaction model, which permitted the description of only two-dimensional atomic localization within an OSL. The present work generalizes these results to the case of four-level atoms with an F = 0 → F = 1 transition and a 3D configuration of multi-frequency optical fields.

Jayampathi Kangara, Jayampathi Chamila Bandara

I. V. Krasnov

Abstract In this paper, we show the use of the combination of co-propagating cosine-Gaussian laser beams to generate a deep three-dimensional (3D) optical superlattice for resonant particles (atoms, ions and similar ones). The method is based on the Talbot effect, non-diffracting properties of the cosine-Gaussian light beams and 3D rectification of a gradient force in a strong bichromatic field.