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Realization of a fractional period adiabatic superlattice

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 Added by Ian Spielman
 Publication date 2019
  fields Physics
and research's language is English




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We propose and realize a deeply sub-wavelength optical lattice for ultracold neutral atoms using $N$ resonantly Raman-coupled internal degrees of freedom. Although counter-propagating lasers with wavelength $lambda$ provided two-photon Raman coupling, the resultant lattice-period was $lambda/2N$, an $N$-fold reduction as compared to the conventional $lambda/2$ lattice period. We experimentally demonstrated this lattice built from the three $F=1$ Zeeman states of a $^{87}{rm Rb}$ Bose-Einstein condensate, and generated a lattice with a $lambda/6= 132 {rm nm}$ period from $lambda=790 {rm nm}$ 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 $lambda/2$ unit cell.



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