The Poisson ratio of crystalline surfaces

TL;DR

This paper confirms through large-scale simulations that crystalline surfaces can have a negative Poisson ratio, specifically around -0.32, aligning with theoretical predictions, which challenges typical material behavior.

Contribution

The study provides the first numerical verification of a negative Poisson ratio in crystalline surfaces, supporting theoretical models with precise simulation data.

Findings

Poisson ratio approximately -0.32 at specific conditions

Simulation results agree with theoretical prediction of -1/3

Crystalline surfaces can exhibit auxetic behavior

Abstract

A remarkable theoretical prediction for a crystalline (polymerized) surface is that its Poisson ratio (\sigma) is negative. Using a large scale Monte Carlo simulation of a simple model of such surfaces we show that this is indeed true. The precise numerical value we find is (\sigma \simeq -0.32) on a (128^2) lattice at bending rigidity (kappa = 1.1). This is in excellent agreement with the prediction (\sigma = -1/3) following from the self-consistent screening approximation of Le Doussal and Radzihovsky.