Doubly dressed states for near-field trapping and subwavelength lattice structuring

Maxime Bellouvet, Caroline Busquet, Jinyi Zhang, Philippe Lalanne, Philippe Bouyer, and Simon Bernon

Phys. Rev. A 98, 023429 (2018)

arxiv : https://doi.org/10.48550/arXiv.1710.05696

We propose a scheme to tailor nanostructured trapping potentials for ultracold atoms. Our trapping scheme combines an engineered extension of repulsive optical dipole forces at short distances and attractive Casimir-Polder forces at long distances between an atom and a nanostructured surface. This extended dipole force scheme takes advantage of excited-state dressing by plasmonically-enhanced optical fields to doubly dress the ground state and create a strongly repulsive potential with spatially tunable characteristics. In this paper, we show that, under realistic experimental conditions, this method can be used to trap Rubidium atoms close to surfaces (tens of nanometers). The influence of the various losses and heating rate mechanism in such traps is characterized. As an example we present a near-field optical lattice with subwavelength period (100 nm) and study the tunability of lattice and trapping depths. Such lattices can enhance energy scales with interesting perspectives for the simulation of strongly-correlated physics. Our method can be extended to other atomic species and to other cold atom near-field hybrid systems.