Doping-Induced Quantum Spin Hall Insulator to Superconductor Transition

A quantum spin Hall insulating state that arises from spontaneous symmetry breaking has remarkable properties: skyrmion textures of the SO(3) order parameter carry charge 2e. Doping this state of matter opens a new route to superconductivity via the condensation of skyrmions. We define a model amenable to large-scale negative sign free quantum Monte Carlo simulations that allows us to study this transition. Our results support a direct and continuous doping-induced transition between the quantum spin Hall insulator and an s-wave superconductor. We can resolve dopings away from half-filling down to delta = 0.0017. Such routes to superconductivity have been put forward in the realm of twisted bilayer graphene.

Automated summary

The study reveals new properties of the quantum spin Hall insulating state, paving the way for superconductivity through the condensation of skyrmions. Through simulations, it is confirmed that there is a direct transition between the quantum spin Hall insulator and an s-wave superconductor, with the ability to analyze dopings away from half-filling. This route to superconductivity has been proposed in the realm of twisted bilayer graphene.