Phase transitions and topological defects in curved space

DA VEGA; GOMEZ LR; CATALINI, G.; PEZZUTTI A; GARCIA NA

Fox do Iguazu

Encuentro; Encontro de Outono da SBF 2018; 2018

Sociedad Brasilera de Física

Here we study the processes of phase separation and self-organization of block copolymer thin ¯lms in curvedspace. Experiments and a phase ¯eld Guinzburg-Landau approach are employed to analyze the couplingbetween textures with hexagonal and smectic symmetries and the local mean and Gaussian curvatures ofthe thin ¯lm. Mechanisms of phase separation, defect formation and defect dynamics are found to stronglydeviate from their counterparts in °at space [1-3]. At the onset of a phase transition, in curved systems theearly density of defects becomes highly inhomogeneous and even a single growing crystal can produce varyingdensities of defects. Thus, non-euclidean geometry is a robust mechanisms to stabilize exotic structures oftopological defects. In addition, we also demonstrate experimentally, theoretically, and through simulationsthat defects in free-standing membranes can act as sources of Gaussian curvature, which can have importantimplications in the use of smectic ¯lms in the development of novel defect-prescribed shapes [4].