A MONTE-CARLO ALGORITHM FOR LATTICE RIBBONS

A lattice ribbon is a connected sequence of plaquettes subject to cert ain self-avoidance conditions. The ribbon can be closed to form an obj ect which is topologically either a cylinder or a Mobius band, dependi ng on whether its surface is orientable or nonorientable. We describe a grand canonical Monte Carlo algorithm for generating a sample of the se ribbons, prove that the associated Markow chain is ergodic, and pre sent and discuss numerical results about the dimensions and entangleme nt complexity of the ribbons.