Structural transition and fragmentation of vortex lattices in rotating tilted dipolar Bose-Einstein condensate

TL;DR

This paper studies how vortex lattice structures in tilted dipolar Bose-Einstein condensates change with tilt angle and rotation, revealing transitions from square to triangular lattices and vortex-free elongated states, influenced by beyond mean-field effects.

Contribution

It introduces a detailed analysis of vortex lattice transformations and fragmentation in rotating dipolar BECs, incorporating Lee-Huang-Yang corrections to capture beyond mean-field phenomena.

Findings

Vortex lattices transition from square to triangular as tilt approaches a critical angle.

Beyond the critical tilt, the condensate elongates and loses vortices.

Lee-Huang-Yang correction induces vortex formation in elongated condensates and causes fragmentation under strong rotation.

Abstract

We investigate the vortex lattices of harmonically confined quasi-two-dimensional tilted rotational dipolar Bose-Einstein condensates. By employing an extended Gross-Pitaevskii equation for a rotating condensate, we reveal the structural transformation of vortices from square to triangular lattices as the tilt of dipolar bosons relative to the polarization axis approaches a critical angle. When the tilt of the magnetic dipoles surpasses the magic angle, the condensate elongates diagonally and becomes devoid of vortices. Moreover, we include the Lee-Huang-Yang correction, which enables the formation of vortices in the elongated condensate. Additionally, when dipoles are oriented perpendicular to the polarization axis, the Lee-Huang-Yang correction results in the fragmentation of condensates under strong rotation. The quench dynamics of the rotational frequency demonstrate the development of vortex lattices; however, with a strong rotational quench, the condensate remains free of vortices. Our numerical analysis highlights the beyond mean-field effects of the rotational properties of anisotropic dipolar bosons, which can be observed in current dipolar quantum gas experiments.