Disorder-induced conducting edges on Kagomé lattice

Abstract

Within a cluster extension of the coherent potential approximation, disorder averaging generates a non-local self-energy that renormalizes both diagonal and off-diagonal hopping terms of the non-interacting Kagome-lattice Hamiltonian. These renormalizations (of both nearest- and next-nearest-neighbor hopping amplitudes) drive the system between two topologically trivial insulating states through an intermediate gapless phase characterized by conducting edge modes over a broad range of impurity concentrations. Our results demonstrate that multiple-scattering effects alone can generate emergent effective spin-orbit interactions and qualitatively modify the edge spectrum of disordered Kagome systems.