arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1012.0313cond-mat.stat-mechcond-mat.soft
收藏

晶体体模膜的非局部有效平均值action方法

Nonlocal effective average action approach to crystalline phantom membranes

N. Hasselmann, F. L. Braghin

摘要:

我们研究了晶体幻影膜的性质,在褶皱过渡和在平坦的阶段,使用非微扰重整化群的方法。我们避免了有效平均作用的导数展开,而是分析弹性耦合函数的全部动量依赖性。这导致了一个更准确的确定的临界指数,并进一步产生完整的动量依赖性的关联函数的面内和面外的波动。流动方程数值求解D=2维膜嵌入在一个d=3维空间。在我们的方法中,我们发现了一个皱曲转变的第二阶,其特征在于由一个反常的指数$η_c\approx 0.63(8)$和热指数$ν\approx 0.69$。在皱曲转变附近,扁平相的序参量为零,并具有一个临界指数$β\approx 0.22$。平坦相的反常维数为$η_f\approx 0.85$,平坦相中的泊松比为$σ_f\approx -1/3$ .在皱曲转变处,我们发现泊松比$σ_c \approx -0.71(5)$有一个大得多的负值。我们进一步详细讨论了不同的制度的动量相关的波动,无论是在平坦的阶段,并在附近的皱曲过渡,并提取交叉动量尺度分开它们。

英文摘要:

We investigate the properties of crystalline phantom membranes, at the crumpling transition and in the flat phase, using a nonperturbative renormalization group approach. We avoid a derivative expansion of the effective average action and instead analyse the full momentum dependence of the elastic coupling functions. This leads to a more accurate determination of the critical exponents and further yields the full momentum dependence of the correlation functions of the in-plane and out-of-plane fluctuation. The flow equations are solved numerically for D=2 dimensional membranes embedded in a d=3 dimensional space. Within our approach we find a crumpling transition of second order which is characterized by an anomalous exponent $η_c\approx 0.63(8)$ and the thermal exponent $ν\approx 0.69$. Near the crumpling transition the order parameter of the flat phase vanishes with a critical exponent $β\approx 0.22$. The flat phase anomalous dimension is $η_f\approx 0.85$ and the Poisson's ratio inside the flat phase is found to be $σ_f\approx -1/3$. At the crumpling transition we find a much larger negative value of the Poisson's ratio $σ_c \approx -0.71(5)$. We discuss further in detail the different regimes of the momentum dependent fluctuations, both in the flat phase and in the vicinity of the crumpling transition, and extract the crossover momentum scales which separate them.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑