Radio-frequency control of the Lande factor of Bose-condensed chromium atoms

We study the effect of strong radio-frequency (rf) fields on a chromium Bose-Einstein condensate, in a regime where the rf frequency is much larger than the Larmor frequency. We show that the Lande factor of the atoms is lowered by the presence of the rf, and can be even set to zero for a proper combination of the rf power and frequency. The trajectories of the atoms under the influence of magnetic potentials are thus greatly modified. We study the criteria for adiabaticity of the rf dressing process leading to such a modification of the atom magnetic susceptibility. We also measure the lifetime of the rf dressed BECs.