Entanglement properties of atoms near a Feshbach resonance

We investigate the motional entanglement between two neutral atoms in a spherical harmonic trap going beyond the contact-interaction approximation by adopting a finite-range interaction model. Tuning the interatomic interactions near a Feshbach resonance allows for the exploration of different interaction regimes including the regime where the s-wave scattering length is larger than the oscillator length. The entanglement properties of the system are extracted from the Schmidt decomposition of the atomic wavefunction obtained by numerically solving the two-body Schrodinger equation for different interaction models. We compare the motional entanglement induced by the standard Lennard-Jones potential with that where a repulsive barrier is introduced to mimic open and closed channel couplings, characterizing broad and narrow Feshbach resonances. The dependence of the Schmidt coefficients on the s-wave scattering length is presented for both broad and narrow resonances to illustrate the impact of the resonance strength on the motional entanglement in the system.