Realization of a stroboscopic optical lattice for cold atoms with subwavelength spacing

TL;DR

This paper demonstrates a novel method to create a subwavelength optical lattice with quarter-wavelength spacing using stroboscopic phase-shifted potentials, enabling new possibilities for cold atom experiments.

Contribution

The authors introduce a stroboscopic technique to realize a $$-spaced optical lattice using dark states, surpassing diffraction limits of traditional lattices.

Findings

Successfully created a -spaced lattice with stroboscopic phase shifts.

Measured atomic lifetimes within the new lattice structure.

Analyzed mechanisms limiting the lattice's applicability.

Abstract

Optical lattices are typically created via the ac-Stark shift, which are limited by diffraction to periodicities $\ge\lambda/2$, where $\lambda$ is the wavelength of light used to create them. Lattices with smaller periodicities may be useful for many-body physics with cold atoms and can be generated by stroboscopic application of a phase-shifted lattice with subwavelength features. Here we demonstrate a $\lambda/4$-spaced lattice by stroboscopically applying optical Kronig-Penney(KP)-like potentials which are generated using spatially dependent dark states. We directly probe the periodicity of the $\lambda/4$-spaced lattice by measuring the average probability density of the atoms loaded into the ground band of the lattice. We measure lifetimes of atoms in this lattice and discuss the mechanisms that limit the applicability of this stroboscopic approach.