Realization of a deeply subwavelength adiabatic optical lattice

We propose and describe our realization of a deeply subwavelength optical lattice for ultracold neutral atoms using N resonantly Raman-coupled internal degrees of freedom. Although counterpropagating lasers with wavelength λ provided two-photon Raman coupling, the resultant lattice period was λ/2N, an N-fold reduction as compared to the conventional λ/2 lattice period. We experimentally demonstrated this lattice built from the three F=1 Zeeman states of a 87Rb Bose-Einstein condensate, and generated a lattice with a λ/6=132nm period from λ=790nm lasers. Lastly, we show that adding an additional rf-coupling field converts this lattice into a superlattice with N wells uniformly spaced within the original λ/2 unit cell.

Realization of a deeply subwavelength adiabatic optical lattice; R. P. Anderson, D. Trypogeorgos, A. Valdés-Curiel, Q.-Y. Liang, J. Tao, M. Zhao, T. Andrijauskas, G. Juzeliūnas, and I. B. Spielman; Phys. Rev. Research 2 013149 (2020). doi:10.1103/PhysRevResearch.2.013149

https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearch.2.013149