Interplay between shell structure and trap deformation in dipolar Fermi gases

Finite fermion systems are known to exhibit shell structure in the weakly interacting regime, as is well known from atoms, nuclei, metallic clusters, or even quantum dots in two dimensions. All these systems have in common that the particle interactions between electrons or nucleons are spatially isotropic. Dipolar quantum systems as they have been realized with ultracold gases, however, are governed by an intrinsic anisotropy of the two-body interaction that depends on the orientation of the dipoles relative to each other. Here we investigate how this interaction anisotropy modifies the shell structure in a weakly interacting two-dimensional anisotropic harmonic trap. Going beyond Hartree-Fock analysis by applying the so-called importance-truncated configuration-interaction (CI) method as well as quadratic CI with single and double substitutions, we show how the magnetostriction in the system may be counteracted upon by a deformation of the confinement.