Realization of a fractional period adiabatic superlattice
Abstract
We propose and realize a deeply subwavelength optical lattice for ultracold neutral atoms using $N$ resonantly Ramancoupled internal degrees of freedom. Although counterpropagating lasers with wavelength $\lambda$ provided twophoton Raman coupling, the resultant latticeperiod 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 $^{87}{\rm Rb}$ BoseEinstein 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.
 Publication:

arXiv eprints
 Pub Date:
 July 2019
 arXiv:
 arXiv:1907.08910
 Bibcode:
 2019arXiv190708910A
 Keywords:

 Condensed Matter  Quantum Gases;
 Physics  Atomic Physics;
 Quantum Physics
 EPrint:
 5 pagesl 4 figures