Xing Xiangjun, Radzihovsky Leo
Department of Physics, University of Colorado, Boulder, Colorado 80309, USA.
Phys Rev Lett. 2003 Apr 25;90(16):168301. doi: 10.1103/PhysRevLett.90.168301. Epub 2003 Apr 21.
We study elasticity of spontaneously orientationally ordered amorphous solids, characterized by a vanishing transverse shear modulus, as realized by nematic elastomers and gels. We show that local heterogeneities and elastic nonlinearities conspire to lead to anomalous nonlocal universal elasticity controlled by a nontrivial infrared fixed point. Namely, such solids are characterized by universal shear and bending moduli that, respectively, vanish and diverge at long scales, are universally incompressible, and exhibit a universal negative Poisson ratio and a non-Hookean elasticity down to arbitrarily low strains. Based on expansion about five dimensions, we argue that the nematic order is stable to thermal fluctuation and local heterogeneities down to d(lc)<3.
我们研究了自发取向有序非晶态固体的弹性，这类固体的特征是横向剪切模量为零，向列型弹性体和凝胶可实现这一特性。我们表明，局部不均匀性和弹性非线性共同作用，导致了由一个非平凡红外不动点控制的反常非局部普适弹性。具体而言，这类固体具有普适剪切模量和弯曲模量，在长尺度下，剪切模量分别消失而弯曲模量发散，它们普遍不可压缩，并且呈现出普适负泊松比以及低至任意低应变下的非胡克弹性。基于五维展开，我们认为向列序对于热涨落和局部不均匀性是稳定的，直至d(lc)<3。
