Vortex structures of rotating spin-orbit-coupled Bose-Einstein condensates

We consider the quasi-two-dimensional two-component Bose-Einstein condensates with Rashba spin-orbit (SO) coupling in a rotating trap. The rotation angular velocity couples to the mechanical angular momentum, which contains a noncanonical part arising from SO coupling. The effects of an external Zeeman term favoring spin polarization along the radial direction is also considered, which has the same form as the noncanonical part of the mechanical angular momentum. The rotating condensate exhibits a variety of rich structures by varying the strengths of the trapping potential and interaction. With a strong trapping potential, the condensate exhibits a half-quantum vortex-lattice configuration. Such a configuration is driven to the normal one by introducing the external radial Zeeman field. In the case of a weak trap potential, the condensate exhibits a multidomain pattern of plane-wave states under the external radial Zeeman field.