Controlling the Interactions of Ultracold Atoms Using Anharmonic Optical Potentials

Luming Duan

Philip R. Johnson, Eite Tiesinga, Xiangyu Yin +1 more

Gediminas Juzeliūnas, Patrik Öhberg

J. P. Kestner, L-M Duan

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.

M. Inguscio

Mateusz Łącki

Using an optical potential with subwavelength resolution in the form of sharp $\ensuremath{\delta}$-like peaks, potential landscapes are created with increased anharmonicity in placement of lattice band energies and more favorable energy scales. In particular, this makes the ultracold atom $p$-band gas more stable. The article outlines the details of the construction and discusses the $p$-band stability in a canonical cosine optical lattice potential, double-well potential, and a combination of a classical cosine potential with dark state peaked potential.