  Two-dimensional crystalline membranes have recently been realized
experimentally in such systems as graphene and molybdenum disulfide, sparking a
resurgence in interest in their statistical properties. Thermal fluctuations
can significantly affect the effective mechanical properties of properly
thermalized membranes, renormalizing both bending rigidity and elastic moduli
so that in particular they become stiffer to bending than their bare bending
rigidity would suggest. We use molecular dynamics simulations to examine how
the mechanical behavior of thermalized two-dimensional clamped ribbons
(cantilevers) depends on their precise topology and geometry. We find that a
simple slit smooths roughness as measured by the variance of height
fluctuations. This counterintuitive effect may be due to the counter-posed
coupling of the lips of the slit to twist in the intact regions of the ribbon.
