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

TL;DR

This paper introduces a novel method for trapping ultracold atoms near nanostructured surfaces using doubly-dressed optical potentials, enabling subwavelength lattice formation for advanced quantum simulations.

Contribution

It presents a new scheme combining engineered dipole and Casimir-Polder forces with excited-state dressing to create tunable, strongly repulsive near-field traps and subwavelength optical lattices.

Findings

Traps Rubidium atoms within tens of nanometers of surfaces.

Realistic conditions allow creation of 100nm period optical lattices.

Characterization of losses and heating mechanisms in near-field traps.

Abstract

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 takes advantage of excited-state dressing by plasmonically-enhanced intensity to doubly dress the ground state and create a strongly repulsive potential with spatially tunable characteristics. In this work, we show that, under realistic experimental conditions, this method can be used to trap Rubidium atoms close to surfaces (tens of nanometers) or to realize nanostructured lattices with subwavelength periods. 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 100nm period 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 near-field hybrid systems where a strong atom-light interaction can be expected.