title: Anisotropy-induced Feshbach resonances in a quantum dipolar gas of highly magnetic atoms.
abstract: We explore the anisotropic nature of Feshbach resonances in the collision between ultracold highly magnetic submerged-shell dysprosium atoms in their energetically lowest magnetic sublevel, which can only occur due to couplings to rotating bound states. This is in contrast to well-studied alkali-metal atom collisions, where broadest (strongest) Feshbach resonances are hyperfine induced and due to rotationless bound states. Our first-principle coupled-channel calculation of the collisions between these spin-polarized bosonic dysprosium atoms reveals a strong interplay between the anisotropies in the dispersion and magnetic dipole-dipole interaction. The former anisotropy is absent in alkali-metal and chromium collisions. We show that both types of anisotropy significantly affect the Feshbach spectrum as a function of an external magnetic field. Effects of the electrostatic quadrupole-quadrupole interaction are small. Over a 20 mT magnetic field range, we predict about 10 Feshbach resonances and show that the resonance locations depend on the dysprosium isotope.
authors.affiliation: Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Petrov
authors.forename: Eite
authors.initials: E
authors.lastname: Tiesinga
authors.forename: Svetlana
authors.initials: S
authors.lastname: Kotochigova