Now published in PRA with collaborators from JILA, Boulder (Colorado, USA), we accurately determine the scattering length for the four bosonic erbium isotopes with highest abundance in the magnetic field range from 0G to 5G. We use the cross-dimensional thermalization technique and extract the scattering length by applying a fit of the complete Enskog equations of change and by utilizing an analytic formula for the so-called number of collisions per re-thermalization. We benchmark our results with the very accurate but experimentally more demanding lattice modulation spectroscopy, confirming the accuracy of our experimental protocol.
The paper can be accessed here: Phys. Rev. A, and the pre-print here: arXiv