Optical lattice with spin-dependent sub-wavelength barriers

TL;DR

This paper proposes a method to create spin-dependent sub-wavelength optical lattices using a tripod atom-light coupling scheme, enabling flexible control of atomic motion and potential applications in spin ordering.

Contribution

It introduces a novel tripod scheme to generate spin-dependent sub-wavelength barriers, expanding the capabilities of optical lattices with current experimental techniques.

Findings

Able to switch between different atomic motion regimes

Spectrum significantly altered by laser configuration

Lattice can be realized with existing technology

Abstract

We analyze a tripod atom light coupling scheme characterized by two dark states playing the role of quasi-spin states. It is demonstrated that by properly configuring the coupling laser fields, one can create a lattice with spin-dependent sub-wavelength barriers. This allows to flexibly alter the atomic motion ranging from atomic dynamics in the effective brick-wall type lattice to free motion of atoms in one dark state and a tight binding lattice with a twice smaller periodicity for atoms in the other dark state. Between the two regimes, the spectrum undergoes significant changes controlled by the laser fields. The tripod lattice can be produced using current experimental techniques. The use of the tripod scheme to create a lattice of degenerate dark states opens new possibilities for spin ordering and symmetry breaking.