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arXiv · 1101.6026

Suppression of anharmonicities in crystalline membranes by external strain

Abstract

In practice, physical membranes are exposed to a certain amount of external strain (tension or compression), due to the environment where they are placed. As a result, the behavior of the phonon modes of the membrane is modified. We show that anharmonic effects in stiff two-dimensional membranes are highly suppressed under the application of tension. For this, we consider the anharmonic coupling between bending and stretching modes in the self-consistent screening approximation (SCSA), and compare the obtained height-height correlation function in the SCSA to the corresponding harmonic propagator. The elasticity theory results are compared to atomistic Monte Carlo simulations for a graphene membrane under tension. We find that, while rather high values of strain are needed to avoid anharmonicity in soft membranes, strain fields less than 1% are enough to suppress all the anharmonic effects in stiff membranes, as graphene.

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Rafael Roldán, Annalisa Fasolino, Kostyantyn V. Zakharchenko, Mikhail I. Katsnelson. 2011-05-11. Suppression of anharmonicities in crystalline membranes by external strain. https://doi.org/10.1103/physrevb.83.174104

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