# Dark-State Optical Potential Barriers with Nanoscale Spacing

## TL;DR

This paper proposes a method to create nanoscale optical potential barriers using dark states in atomic systems, enabling long-lived bound states and advancing control over atomic interactions at subwavelength scales.

## Contribution

It introduces a novel approach to generate multiple subwavelength optical barriers via dark states, expanding the landscape of non-adiabatic potentials for cold atom manipulation.

## Key findings

- Long-lived bound states with lifetimes of seconds achieved.
- Nanoscale barriers created with subwavelength spacing.
- Discussion of experimental imperfections and realizations.

## Abstract

Optical potentials have been a versatile tool for the study of atomic motions and many-body interactions in cold atoms. Recently, optical subwavelength single barriers were proposed to enhance the atomic interaction energy scale, which is based on non-adiabatic corrections to Born-Oppenheimer potentials. Here we present a study for creating a new landscape of non-adiabatic potentials--multiple barriers with subwavelength spacing at tens of nanometers. To realize these potentials, spatially rapid-varying dark states of atomic $\Lambda$-configurations are formed by controlling the spatial intensities of the driving lasers. As an application, we show that bound states of very long lifetimes on the order of seconds can be realized. Imperfections and experimental realizations of the multiple barriers are also discussed.