Reconfigurable nematic disclination patterns stabilized by topographically patterned surfaces

Reconfigurable metastable defect configurations in nematic liquid crystals (LCs) have the potential to be utilized in various technological applications such as responsive materials and LC displays. We investigate the large space of multistable configurations of disclination lines arising in a hybrid-aligned nematic LC with a double-undulated, homeotropic boundary and a flat boundary with degenerate planar anchoring. The application of an electric field in this system allows for the reconfiguration of the disclination lines, and possibly provides a pathway for switching between metastable configurations. We use Landau-de Gennes modeling to investigate the influence of confining surface geometry on the assembly of patterns of disclination lines in this double-undulated system. We establish the rules of formation of the defect configurations, and characterize the disclination lines through the calculation of the rotation vector, describing the defect's local winding. Along with these calculations, we use energetic arguments to elucidate the heterogeneity of the multistable disclination landscape.