Finite fermion systems are known to exhibit shell structure in the weakly-interacting regime, as 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 ultra-cold 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 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 isotropic confinement.

中文翻译：

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偶极费米气体中壳结构与陷阱陷阱之间的相互作用

众所周知，有限的费米子系统在弱相互作用状态下表现出壳结构，这是从二维的原子，原子核，金属簇甚至量子点中得知的。所有这些系统的共同点是，电子或核子之间的粒子相互作用是空间各向同性的。然而，已经用超冷气体实现的偶极子量子系统受两体相互作用的固有各向异性支配，该固有各向异性取决于偶极子相对于彼此的取向。在这里，我们研究了这种相互作用的各向异性如何在弱相互作用的二维各向异性谐波阱中改变壳结构。通过应用所谓的“重要性截断”配置交互（CI）方法以及具有单取代和双取代的二次CI来超越Hartree-Fock，