Corner multifractality for reflex angles and conformal invariance at 2D Anderson metal–insulator transition with spin–orbit scattering

We investigate boundary multifractality of critical wave functions at the Anderson metal–insulator transition in two-dimensional disordered non-interacting electron systems with spin–orbit scattering. We show numerically that multifractal exponents at a corner with an opening angle θ=3π/2 are directly related to those near a straight boundary in the way dictated by conformal symmetry. This result extends our previous numerical results on corner multifractality obtained for θ<π to θ>π, and gives further supporting evidence for conformal invariance at criticality. We also propose a refinement of the validity of the symmetry relation of A.D. Mirlin et al. [Phys. Rev. Lett. 97 (2006) 046803] for corners.