Production of strongly bound 39K bright solitons
  We report on the production of 39 K matter-wave bright solitons, i.e., 1D matter-waves that propagate without dispersion thanks to attractive interactions. The volume of the soliton is studied as a function of the scattering length through three-body losses, revealing peak densities as high as $\sim 5 \times 10^{20} m^{-3}$. Our solitons, close to the collapse threshold, are strongly bound and will find applications in fundamental physics and atom interferometry. 
S Lepoutre, L Fouch\'e, A Boiss\'e, G Berthet, G Salomon, A Aspect, T   Bourdel
physics.atom-ph cond-mat.quant-gas