Realization of a deeply subwavelength adiabatic optical lattice

Abstract

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 87 Rb Bose-Einstein condensate, and generated a lattice with a λ/6 = 132 nm period from λ = 790 nm 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.

Optical lattice with spin-dependent sub-wavelength barriers

“…The characteristic distances over which optical lattice potentials change are limited by diffraction and thus cannot be smaller than half of the optical wavelength λ. Yet the diffraction limit does not necessarily apply to optical lattices [5][6][7][8][9] or other sub-wavelength structures [10][11][12][13][14][15][16][17] relying on coherent coupling between atomic internal states.…”

Dynamical preparation of stripe states in spin-orbit-coupled gases

“…These amplitudes are compatible with a magnetic bias field instability of approximately 0.5 mG and a relative uncertainty of ±5% in Ω, within the stabilities reached in experiments with 87 Rb [7,69,76]. At the same time we consider a 10% uncertainty in the number of atoms initially in the condensate and the population to decay as N (t) = N (0) exp(−γt), with γ = 3.33 s −1 , which is compatible with the lifetime of spin-1 Raman-dressed BECs for Ω < E r [69,77].…”

Laughlin's topological charge pump in an atomic Hall cylinder

“…3D). The q-variation of these distributions reveals a chirality typical of the Hall effect: when increasing the momentum by 2k, the P y distributions cycle along the synthetic dimension in a directional manner, as P y → P y+1 [27,28]. We stress that such a drift does not occur on the mean spin projection m , which remains close to zero (red line in Fig.…”