Influence of boundary conditions on the order and defects of biaxial nematic droplets.

We employ Monte Carlo simulations to study the defects occurring in a nematic droplet formed by biaxial molecules. The simulations are carried out using a lattice model based on a dispersive orientational biaxial potential previously employed to establish the rich phase diagram of the system. The focus of the present investigation is on the molecular organization inside the droplet when bipolar and toroidal anchoring conditions at the surface are considered. In both cases, we describe how the defect structure arises in the system, and we analyze the behavior of the defect core region in connection with the elastic properties of the phase in a continuum theory perspective.