EPR pairing dynamics in Hubbard model with resonant U

We study the dynamics of the collision between two fermions in Hubbard model with on-site interaction strength U. The exact solution shows that the scattering matrix for two-wavepacket collision is separable into two independent parts, operating on spatial and spin degrees of freedom, respectively. The S-matrix for spin configuration is equivalent to that of Heisenberg-type pulsed interaction with the strength depending on U and relative group velocity v(r). This can be applied to create distant EPR pair, through a collision process for two fermions with opposite spins in the case of |v(r)/U| = 1, without the need for temporal control and measurement process. Multiple collision process for many particles is also discussed.