Crystal Structures of Two-Dimensional Binary Mixtures of Dipolar Colloids in Tilted External Magnetic Fields

We employ genetic algorithms, which allow for an efficient search for the global minimum of energy landscapes, to investigate the ordered equilibrium structures formed by a binary mixture of anisotropic dipolar particles confined on a plane, under the influence of an external magnetic field. The anisotropy is introduced by titling the external field with respect to the interface, and it is tuned by the degree of the tilt angle. For small tilt angles, the structures obtained for perpendicular fields are slightly perturbed but beyond system-dependent values of the tilt, novel structures emerge, characterized by the formation of complex arrangements of chains that lie parallel to the in-plane projection of the field.