Anharmonicity Induced Resonances for Ultracold Atoms and their Detection

TL;DR

This paper explores how anharmonic potentials in optical lattices induce new atomic resonances, affecting interactions and providing a method for experimental detection via magnetic field sweeps.

Contribution

It demonstrates the existence of anharmonicity-induced resonances and offers a quantitative analysis and detection scheme in optical superlattices.

Findings

Identification of new resonances due to anharmonicity

Quantitative characterization in optical superlattices

Proposed experimental detection method

Abstract

When two atoms interact in the presence of an anharmonic potential, such as an optical lattice, the center of mass motion cannot be separated from the relative motion. In addition to generating a confinement-induced resonance (or shifting the position of an existing Feshbach resonance), the external potential changes the resonance picture qualitatively by introducing new resonances where molecular excited center of mass states cross the scattering threshold. We demonstrate the existence of these resonances, give their quantitative characterization in an optical superlattice, and propose an experimental scheme to detect them through controlled sweeping of the magnetic field.