  The two-component Fermi gas with contact attractive interactions between
different spin components can be described by the Yang-Gaudin model. Applying
the Bethe ansatz approach, one finds analytical formulae for the system
eigenstates that are uniquely parametrized by the solutions of the
corresponding Bethe equations. Recent numerical studies of the so-called yrast
eigenstates, i.e. lowest energy eigenstates at a given non-zero total momentum,
in the Yang-Gaudin model show that their spectrum resembles yrast dispersion
relation of the Lieb-Liniger model which in turn matches the dark soliton
dispersion relation obtained within the nonlinear Schr\"{o}dinger equation. It
was shown that such conjecture in the case of the Lieb-Liniger model was not
accidental and that dark soliton features emerged in the course of measurement
of positions of particles, when the system was initially prepared in an yrast
eigenstate. Here, we demonstrate that, starting with yrast eigenstates in the
Yang-Gaudin model, the key soliton signatures are revealed by the measurement
of pairs of fermions. We study soliton signatures in a wide range of the
interaction strength.
