Multifractality and conformal invariance at 2D metal-insulator transition in the spin-orbit symmetry class.
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.
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Condensed Matter Theory Laboratory, RIKEN, Wako, Saitama 351-0198, Japan.
Subramaniam
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Furusaki
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Gruzberg
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Ludwig
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AW