Dynamic optical lattices of sub-wavelength spacing for ultracold atoms

TL;DR

This paper introduces a scheme to create sub-wavelength optical lattices for ultracold atoms using spin-dependent, time-modulated optical potentials, enabling exploration of strongly-correlated and topological quantum states.

Contribution

It proposes a novel method for generating sub-wavelength optical lattices with tunable properties using spin-dependent, time-periodic modulation.

Findings

Numerical simulations confirm adiabatic loading into the effective lattice ground state.

The scheme can be extended to two-dimensional lattices with non-zero Chern numbers.

Enhanced energy scales may facilitate the realization of strongly-correlated states.

Abstract

We propose a scheme to realize lattice potentials of sub-wavelength spacing for ultracold atoms. It is based on spin-dependent optical lattices with a time-periodic modulation. We show that the atomic motion is well described by the combined action of an effective, time-independent, lattice of small spacing, together with a micro-motion associated with the time-modulation. A numerical simulation shows that an atomic gas can be adiabatically loaded into the effective lattice ground state, for timescales comparable to the ones required for adiabatic loading of standard optical lattices. We generalize our scheme to a two-dimensional geometry, leading to Bloch bands with non-zero Chern numbers. The realization of lattices of sub-wavelength spacing allows for the enhancement of energy scales, which could facilitate the achievment of strongly-correlated (topological) states.