A Kaleidoscope of Topological Structures in Dipolar Bose-Einstein Condensates with Weyl-Like Spin-Orbit Coupling in Anharmonic Trap

TL;DR

This paper explores the rich variety of topological structures in dipolar Bose-Einstein condensates with Weyl-like spin-orbit coupling, revealing new quantum states, defects, and critical behaviors influenced by interactions, rotation, and trap anharmonicity.

Contribution

It systematically analyzes how dipole interactions, Weyl-like SOC, rotation, and anharmonic traps create diverse topological quantum states and defects in BECs, including fractional skyrmions.

Findings

Discovery of kaleidoscope of quantum states including droplets and lattice structures

Identification of exotic spin topological structures like fractional skyrmions

Observation of critical behavior in topological transitions

Abstract

Dipole-dipole interaction (DDI) possesses characteristics different from the conventional isotropic s-wave interaction in Bose-Einstein condensates (BECs), the interplay of DDI with spin-orbit coupling (SOC) and rotation may induce novel quantum properties. We systematically analyze the effects of the DDI, Weyl-like SOC, rotation and trap anharmonicity in the ground state of two-componen BECs. The interplay of these factors leads to a kaleidoscope of quantum states of quantum defects and quantum droplets in lattice, wheel and ring forms of distributions, with transitions of topology of density and a critical behavior in varying the parameters. We also show a bunch of exotic spin topological structures, including centric vortex surrounded by layers of spin flows, compound topological structure of edge defect, and various coexistence states of skyrmions with different topological charge. In particular, we find quarter skyrmions and other possible fractional skyrmions. Rashba-type SOC and Weyl-like SOC are compared as well. Our study implies that one can manipulate both the density topology and the spin topological structure via these tunable parameters in BECs. The abundant variations of the topological structures and particularly the revealed critical behavior may provide various quantum resources for potential applications in quantum metrology.