Production of strongly bound 39K bright solitons.

We report on the production of 39K matter-wave bright solitons, i.e., one-dimensional 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 ~5×1020m-3. Our solitons, close to the collapse threshold, are strongly bound and will find applications in fundamental physics and atom interferometry. [ABSTRACT FROM AUTHOR]