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

TL;DR

This paper proposes a new method to realize quantum anomalous Hall and quantum spin Hall effects in doped kagome lattice Mott insulators, demonstrated through ab-initio calculations on herbertsmithite, opening pathways for practical topological quantum materials.

Contribution

It introduces doping of kagome lattice Mott insulators as a novel approach to achieve topological effects, supported by theoretical calculations and realistic models.

Findings

Feasibility of doping kagome Mott insulators demonstrated

Predicted quantum Hall effects in doped herbertsmithite

Potential for practical topological insulators at accessible conditions

Abstract

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