Ultratight confinement of atoms in a Rydberg empowered optical lattice

Quantum 9, 1585 (2025).

https://doi.org/10.22331/q-2025-01-08-1585

Optical lattices serve as fundamental building blocks for atomic quantum technology. However, the scale and resolution of these lattices are diffraction-limited to the light wavelength. In conventional lattices, achieving tight confinement of single sites requires high laser intensity, which unfortunately leads to reduced coherence due to increased scattering. This article presents a novel approach for creating an atomic optical lattice with a sub-wavelength spatial structure. The potential is generated by leveraging the nonlinear optical response of three-level Rydberg-dressed atoms, which allows us to overcome the diffraction limit of the driving fields. The resulting lattice comprises a three-dimensional array of ultra-narrow Lorentzian wells over nanometer scales. These unprecedented scales can now be accessed through a hybrid scheme that combines the dipolar interaction and optical twist of atomic eigenstates. The interaction-induced two-body resonance that forms the trapping potential, only occurs at a peculiar laser intensity, localizing the trap sites to ultra-narrow regions over the standing-wave driving field. The feasibility study shows that single-atom confinement in Lorentzian sites with 3nm width, and 37MHz depth are realizable with available lasers. The development of these ultra-narrow trapping techniques holds great promise for applications such as Rydberg-Fermi gates, atomtronics, quantum walks, Hubbard models, and neutral-atom quantum simulation.