Obuse H, Subramaniam A R, Furusaki A, Gruzberg I A, Ludwig A W W
Condensed Matter Theory Laboratory, RIKEN, Wako, Saitama 351-0198, Japan.
Phys Rev Lett. 2007 Apr 13;98(15):156802. doi: 10.1103/PhysRevLett.98.156802. Epub 2007 Apr 12.
We study the multifractality (MF) of critical wave functions at boundaries and corners at the metal-insulator transition (MIT) for noninteracting electrons in the two-dimensional (2D) spin-orbit (symplectic) universality class. We find that the MF exponents near a boundary are different from those in the bulk. The exponents at a corner are found to be directly related to those at a straight boundary through a relation arising from conformal invariance. This provides direct numerical evidence for conformal invariance at the 2D spin-orbit MIT. The presence of boundaries modifies the MF of the whole sample even in the thermodynamic limit.
我们研究了二维（2D）自旋轨道（辛）普适类中非相互作用电子在金属-绝缘体转变（MIT）处边界和角点处临界波函数的多重分形性（MF）。我们发现边界附近的MF指数与体相中的不同。通过共形不变性产生的关系，发现角点处的指数与直边界处的指数直接相关。这为二维自旋轨道MIT处的共形不变性提供了直接的数值证据。即使在热力学极限下，边界的存在也会改变整个样品的MF。
