Publication : t87/102

Abstract:
The long distance behaviour of a model of fluid membranes with orientational (hexatic) order and small surface tension is investigated. It is shown that, if orientational defects (disclinations) are neglected, the hexatic stiffness KA is not renormalized by thermal fluctuations. The renormalization flow of the rigidity modulus kappa goes, at large KA, to a nontrivial infrared stable fixed point. In this situation, hexatic membranes with vanishing effective surface tension are smooth critical objects with a finite fractal dimension dF > 2 and a spreading dimension ds < 2 which depend continuously on KA, in contrast with the case of fluid membranes.