Three-dimensional localization of atoms in the polychromatic optical superlattice

I. V. Krasnov

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

Aranya B. Bhattacherjee

Luca Guidoni, Philippe Verkerk

We present direct experimental evidence for the localization of atoms cooled and trapped in a three- dimensional optical superlattice. As in the case of solid-state superlattices, we are able to tailor the characteristics of the optical potential wells. In particular, we impose a long-range modulation to the depth of the potential wells whose size remains in the optical wavelength range. The cooling mechanism in this configuration accumulates the atoms in the deepest wells. Images of the resulting separated denser atomic planes (distance $\ensuremath{\simeq}70$ $\ensuremath{\mu}\mathrm{m}$) have been obtained both by detecting the fluorescence and by observing the shadow of the cloud.

I. V. Krasnov, L. P. Kamenshchikov

Abstract We demonstrate that the earlier suggested new all-optical method of creating long-term small (containing two or three particles) ion clusters using the rectified optical forces (RFs) can be used to create cold trapped Coulomb crystals (consisting of several tens of resonant ions). The results of the supercomputer simulations of the dynamics of a mercury ion cloud in a polychromatic optical superlattice (induced by RFs) are presented and analysed. Such a cloud (including 49 ions) in the absence of the optical field expands rapidly (during the characteristic time of the order of ) as a result of the Coulomb explosion. It is shown that the polychromatic optical field can result in the ‘quenching’ of the Coulomb explosion and crystallisation of the ion cloud: creation of a quasi-2D array of ordered and strongly coupled cold ions (with the Coulomb coupling parameter and temperature ∼10 −3 K). The mean destruction time of the studied metastable crystal is of the order of 10 s. Moreover, the central core of the ion cloud can retain its crystalline configuration for a much longer time.