Prospect of quantum anomalous Hall and quantum spin Hall effect in doped kagome lattice Mott insulators

摘要

Electronic states with non-trivial topology host a number of novel phenomenawith potential for revolutionizing information technology. The quantumanomalous Hall effect provides spin-polarized dissipation-free transport ofelectrons, while the quantum spin Hall effect in combination withsuperconductivity has been proposed as the basis for realizing decoherence-freequantum computing. We introduce a new strategy for realizing these effects,namely by hole and electron doping kagome lattice Mott insulators through, forinstance, chemical substitution. As an example, we apply this new approach tothe natural mineral herbertsmithite. We prove the feasibility of the proposedmodifications by performing ab-initio density functional theory calculationsand demonstrate the occurrence of the predicted effects using realistic models.Our results herald a new family of quantum anomalous Hall and quantum spin Hallinsulators at affordable energy/temperature scales based on kagome lattices oftransition metal ions.