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

TL;DR

This paper investigates the real-time evolution of two interacting atoms in one-dimensional traps with harmonic and anharmonic potentials following sudden changes in their interaction strength, revealing complex dynamics influenced by initial states and trap anharmonicity.

Contribution

It provides a detailed analysis of the quench dynamics of two particles in anharmonic traps, highlighting the effects of trap anharmonicity and initial states on their evolution.

Findings

Pre- and postquench states influence dynamics interchangeably.

Anharmonic traps introduce additional center-of-mass excitations.

Dynamics differ significantly between harmonic and anharmonic traps.

Abstract

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, wave packet, 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 still could be identified. The quench dynamics of the ground and excited states are considered.