Spin-density separation of spin-orbit coupled Bose-Einstein condensates under rotation

We investigate spatial separation of spin-density in rotating two-component Bose-Einstein condensates that feature spin-orbit coupling of the px sigmay + py sigmaz type. The origin of this separation lies in the fact that, due to the spin-orbit coupling, each component of atoms condenses at opposite points in the pydirection. This separation is further amplified as the rotation frequency increases. The underlying physics can be explained through the use of an ansatz wavepacket in momentum space. In the case of weak density-density interaction and faster rotation, vortex-antivortex pair emerges in the condensates, which exhibits a antimeron pair textures. However, for strong density-density interaction and fast rotation, skyrmions-vortex-antivortex pair lattice forms in the condensates, which feature Neel-type skyrmions textures and antimeron pair textures. We also explore the effects of anisotropic spin-orbit couplings on the spin-density separation.(c) 2023 Elsevier B.V. All rights reserved.