Quench dynamics of two interacting atoms in a one-dimensional anharmonic trap

A temporal response of two interacting particles to a quench of the coupling strength in one-dimensional harmonic and anharmonic traps is explored. The coupling strength is changed from repulsive to attractive interactions and vice versa. The time evolution of the fidelity, one-body reduced density matrix and momentum distributions is analyzed in details. It was found that impacts of the pre-and postquench states interchange during the dynamics. In the case of the anharmonic trap additional contribution of the center-of-mass excited states comes into play and the whole evolution becomes significantly altered. Yet the impact of the pre-and postquench states in some cases can still be identified. The quench dynamics of the ground and excited states are considered.