Fluctuation-induced Topological Quantum Phase Transitions in Quantum Spin Hall and Quantum Anomalous Hall Insulators

摘要

We investigate the role of quantum fluctuations in topological quantum phasetransitions of quantum spin Hall insulators and quantum anomalous Hallinsulators. Employing the variational cluster approximation to obtain thesingle-particle Green's function of the interacting many-body system, wecharacterize different phases by direct calculation of the recently proposedtopological order parameter for interacting systems. We pinpoint the influenceof quantum fluctuations on the quantum spin Hall to Mott insulator transitionin several models. Furthermore, we propose a general mechanism by which atopological quantum phase transition can be driven by the divergence of theself energy induced by interactions.