Sub-wavelength spin excitations in ultracold gases created by stimulated Raman transitions

Abstract

Raman transitions are used in quantum simulations with ultracold atoms for cooling, spectroscopy and creation of artificial gauge fields. Spatial shaping of the Raman fields allows local control of the effective Rabi frequency, which can be mapped to the atomic spin. Evanescent Raman fields are of special interest as they can provide a new degree of control emanating from their rapidly decaying profile and for their ability to generate features below the diffraction limit. This opens the door to the formation of sub-wavelength spin textures. In this work, we present a theoretical and numerical study of Raman Rabi frequency in the presence of evanescent driving fields. We show how spin textures can be created by spatially varying driving fields and demonstrate a skyrmionium lattice - a periodic array of topological spin excitations, each of which is composed of two skyrmions with opposite topological charges. Our results pave the way to quantum simulation of spin excitation dynamics in magnetic materials, especially of itinerant spin models.

12 pages, 3 figures

References in corpus (5)

• Many-Body Physics with Ultracold Gases
• Chiral nanophotonic waveguide interface based on spin-orbit coupling of light
• Subwavelength vacuum lattices and atom-atom interactions in photonic crystals
• Optical Flux Lattices for Ultracold Atomic Gases
• Spin-orbit coupling and Berry phase with ultracold atoms in 2D optical lattices