Coherent Control of Atom Localization by Surface Plasmon Polaritons

This study presents a theoretical framework for achieving subwavelength atomic localization using surface plasmon polaritons (SPPs) in a four-level atomic system. By exploiting the strong field confinement and enhanced near-field effects of SPPs, we demonstrate high-precision atom positioning through quantum interference phenomena. The proposed model utilizes a combination of probe and control fields to generate spatially dependent absorption profiles, enabling atom localization with nanometer-scale resolution. Numerical simulations reveal distinct localization patterns dependent on phase modulation and detuning parameters, with peak resolutions reaching \(\lambda /20\). The interaction between SPPs and atomic states is shown to overcome traditional diffraction limits while maintaining robust coherence properties. These results suggest new possibilities for quantum control at the nanoscale, with direct applications in atom trapping, nanolithography, and plasmon-enhanced spectroscopy. The analysis further identifies optimal conditions for minimizing decoherence effects while maximizing spatial resolution in plasmonic nanostructures.