Radio-frequency induced Feshbach resonances

Quentin Beaufils, A. Crubellier, T. Zanon-Willette +4 more

Ting Xie, Gao‐Ren Wang, Yin Hui Huang +2 more

The heteronuclear atomic collision in the presence of a radio frequency (RF) electric field and a dc magnetic field is investigated theoretically by using the asymptotic bound state model. A RF field can be used to modify Feshbach resonance by choosing suitable intensity and frequency. The control mechanism is based on the interaction of the RF electric field with the instantaneous dipole moment of the collision atomic pair. We find an interesting phenomenon: the character exchange of the Feshbach resonances and resonance interference modulated by the RF field takes place in the ultracold collision of 6 Li and 40 K. This resonance interference may be used to modify the interactions in ultracold quantum gases.

Paul S. Julienne

Bernd Fröhlich, Michael Feld, Enrico Vogt +3 more

We realize and study a strongly interacting two-component atomic Fermi gas confined to two dimensions in an optical lattice. Using radio-frequency spectroscopy we measure the interaction energy of the strongly interacting gas. We observe the confinement-induced Feshbach resonance on the attractive side of the 3D Feshbach resonance and find the existence of confinement-induced molecules in very good agreement with theoretical predictions.

Yijue Ding, José Paulo D'Incao, Chris H. Greene

We study $^{87}\mathrm{Rb}$ cold collisions in a static magnetic field and a single-color radio-frequency (RF) field by employing the multichannel quantum defect theory in combination with the Floquet method to solve the two-body time-dependent Schr\"odinger equation. Our results show that RF fields can modify the two-body scattering length by a large scale through Feshbach resonances in both low- and high-static magnetic-field regimes. Such RF-induced Feshbach resonances can be applied to quenching experiments or control of interactions in spinor condensates. Here, we also show that, analogously to photoassociation, RF fields can also associate cold atoms into molecules at a useful rate.

Hélène Lefebvre-Brion, Annick Giusti-Suzor