Nano-Scale `Dark State' Optical Potentials for Cold Atoms

TL;DR

This paper explores the creation of subwavelength optical barriers for cold atoms using dark states, enabling precise control of atomic potentials at nanometer scales, with implications for quantum simulation and manipulation.

Contribution

It introduces a method to generate subwavelength optical barriers via non-adiabatic corrections to dark states in atomic systems, advancing atomic potential engineering.

Findings

Demonstration of subwavelength optical barriers in atomic systems.

Analysis of bandstructure in optical Kronig-Penney potentials.

Assessment of decoherence effects from spontaneous emission.

Abstract

We discuss generation of subwavelength optical barriers on the scale of tens of nanometers, as conservative optical potentials for cold atoms. These arise from non-adiabatic corrections to Born-Oppenheimer potentials from dressed `dark states' in atomic $\Lambda$-configurations. We illustrate the concepts with a double layer potential for atoms obtained from inserting an optical subwavelength barrier into a well generated by an off-resonant optical lattice, and discuss bound states of pairs of atoms interacting via magnetic dipolar interactions. The subwavelength optical barriers represent an optical `Kronig-Penney' potential. We present a detailed study of the bandstructure in optical `Kronig-Penney' potentials, including decoherence from spontaneous emission and atom loss to open `bright' channels.