论文标题

金属 - 绝缘体过渡和2D无序系统的金属阶段的一般多纹理

Generalized multifractality at metal-insulator transitions and in metallic phases of 2D disordered systems

论文作者

Karcher, Jonas F., Gruzberg, Ilya A., Mirlin, Alexander D.

论文摘要

我们研究了表征对称对称类AII,D和DIII的无序系统中本征态的波动和相关性的广义多纹理性。都考虑了金属阶段和Andersonlocalization跃迁。通过使用非线性Sigma-Model方法,我们构建了纯缩放特征功能可观察物。通过适当的微观模型的数值模拟来验证该构建,该模型还产生相应指数的数值值。在金属阶段,数值获得的指数满足Weyl对称关系以及广义的抛物线(与二次Casimir操作员的特征值相称)。同时,在金属 - 绝缘体过渡的临界点上,广义抛物线受到了强烈侵犯,这表明违反了局部保形不变性。此外,在D类和DIII类中,即使Weyl对称性也在金属 - 绝缘体过渡的临界点上分解。最后一个特征与这些对称类别中的Sigma模型歧管的特殊性有关:它们由两个不相交的组件组成。与这些额外的自由度相关的域墙对于确保安德森本地化至关重要,同时导致违反韦尔对称性。

We study generalized multifractality characterizing fluctuations and correlations of eigenstates in disordered systems of symmetry classes AII, D, and DIII. Both metallic phases and Andersonlocalization transitions are considered. By using the non-linear sigma-model approach, we construct pure-scaling eigenfunction observables. The construction is verified by numerical simulations of appropriate microscopic models, which also yield numerical values of the corresponding exponents. In the metallic phases, the numerically obtained exponents satisfy Weyl symmetry relations as well as generalized parabolicity (proportionality to eigenvalues of the quadratic Casimir operator). At the same time, the generalized parabolicity is strongly violated at critical points of metal-insulator transitions, signalling violation of local conformal invariance. Moreover, in classes D and DIII, even the Weyl symmetry breaks down at critical points of metal-insulator transitions. This last feature is related with a peculiarity of the sigma-model manifolds in these symmetry classes: they consist of two disjoint components. Domain walls associated with these additional degrees of freedom are crucial for ensuring Anderson localization and, at the same time, lead to the violation of the Weyl symmetry.

扫码加入交流群

加入微信交流群

微信交流群二维码

扫码加入学术交流群,获取更多资源