Localizing an atom using Laguerre-Gaussian beams

Abstract: Use of the Laguerre-Gaussian fields in an atom-light interaction makes the linewidth of the optical spectrum narrow. We exploit this fact for providing the ability to accomplish simultaneous ultra-high precision and spatial resolution atom localization in a double-$\Lambda$ atomic system. Under multi-photon resonance condition, the resolution of the localization is remarkably improved so that the atom can be localized in a region smaller than $\lambda/20 \times \lambda/20$. Most prominently, the probability of finding the atom at a particular position is always 100%, when a photon with certain frequencies is absorbed or amplified. Such features are mainly dependent on radial dependence associated with the Laguerre-Gaussian fields in a spatially dependent atom-light interaction.