  The generation of mesoscopic Bell states via collisions of distinguishable
bright solitons has been suggested in Phys. Rev. Lett. 111, 100406 (2013).
Here, we extend our former proposal to two hyperfine states of 85Rb instead of
two different atomic species, thus simplifying possible experimental
realisations. A calculation of the $s$-wave scattering lengths for the
hyperfine states $(f,m_f)=(2,+2)$ and $(3,+2)$ identifies parameter regimes
suitable for the creation of Bell states with an advantageously broad Feshbach
resonance. We show the generation of Bell states using the truncated Wigner
method for the soliton's centre of mass and demonstrate the validity of this
approach by a comparison to a mathematically rigorous effective potential
treatment of the quantum many-particle problem.
