Physics

Stroboscope

Optics

Atomic physics

Diffraction

Acoustics

Superfluidity

Condensed matter physics

Lambda

Lattice (music)

Quantum mechanics

Wavelength

Optical lattice

Physical review. A/Physical review, A

Optical lattices are typically created via the ac Stark shift and are limited by diffraction to periodicities $\ensuremath{\ge}\ensuremath{\lambda}/2$, where $\ensuremath{\lambda}$ 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 $\ensuremath{\lambda}/4$-spaced lattice by stroboscopically applying optical Kronig-Penney-like potentials which are generated using spatially dependent dark states. We directly probe the periodicity of the $\ensuremath{\lambda}/4$-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.

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