Loading and compression of a single two-dimensional Bose gas in an   optical accordion
  The experimental realization of 2D Bose gases with a tunable interaction strength is an important challenge for the study of ultracold quantum matter. Here we report on the realization of an optical accordion creating a lattice potential with a spacing that can be dynamically tuned between 11$\,\mu$m and 2$\,\mu$m. We show that we can load ultracold $^{87}$Rb atoms into a single node of this optical lattice in the large spacing configuration and then decrease nearly adiabatically the spacing to reach a strong harmonic confinement with frequencies larger than $\omega_z/2\pi=10\,$kHz. Atoms are trapped in an additional flat-bottom in-plane potential that is shaped with a high resolution. By combining these tools we create custom-shaped uniform 2D Bose gases with tunable confinement along the transverse direction and hence with a tunable interaction strength. 
J.L. Ville, T. Bienaim\'e, R. Saint-Jalm, L. Corman, M. Aidelsburger,   L. Chomaz, K. Kleinlein, D. Perconte, S. Nascimb\`en...
cond-mat.quant-gas quant-ph