Interatomic interaction effects on second-order momentum correlations and Hong-Ou-Mandel interference of double-well-trapped ultracold fermionic atoms

TL;DR

This paper investigates how interatomic interactions influence second-order momentum correlations and Hong-Ou-Mandel interference patterns in two ultracold fermionic atoms trapped in a double well, revealing interaction-dependent quantum interference effects.

Contribution

It provides a systematic analysis of the evolution of interference patterns in momentum and spatial correlations for interacting fermions using exact diagonalization and Hubbard models.

Findings

Interaction-dependent bunching and antibunching effects observed.

Characteristic interference patterns vary with interaction strength.

Results interpreted in the context of Hong-Ou-Mandel interference.

Abstract

Identification and understanding of the evolution of interference patterns in two-particle momentum correlations as a function of the strength of interatomic interactions are important in explorations of the nature of quantum states of trapped particles. Together with the analysis of two-particle spatial correlations, they offer the prospect of uncovering fundamental symmetries and structure of correlated many-body states, as well as opening vistas into potential control and utilization of correlated quantum states as quantum information resources. With the use of the second-order density matrix constructed via exact diagonalization of the microscopic Hamiltonian, and an analytic Hubbard-type model, we explore here the systematic evolution of characteristic interference patterns in the two-body momentum and spatial correlation maps of two entangled ultracold fermionic atoms in a double well, for the entire attractive- and repulsive-interaction range. We uncover statistics-governed bunching and antibunching, as well as interaction-dependent interference patterns, in the ground and excited states, and interpret our results in light of the Hong-Ou-Mandel interference physics, widely exploited in photon indistinguishability testing and quantum information science.