Resonances in ultracold dipolar atomic and molecular gases

A previously developed approach for the numerical treatment of two particles that are confined in a finite optical-lattice potential and interact via an arbitrary isotropic interaction potential has been extended to incorporate an additional anisotropic dipole-dipole interaction. The interplay of a model but realistic short-range Born-Oppenheimer potential and the dipole-dipole interaction for two confined particles is investigated. A variation of the strength of the dipole-dipole interaction leads to diverse resonance phenomena. In a harmonic confinement potential some resonances show similarities to $s$-wave scattering resonances while in an anharmonic trapping potential like the one of an optical lattice inelastic confinement-induced dipolar resonances occur. The latter are due to a coupling of the relative and center-of-mass motion caused by the anharmonicity of the external confinement.