Reentrant superconductivity in proximity to a topological insulator

Superconducting hybrid structures with topological order and induced magnetization offer a promising way to realize fault-tolerant quantum computation. However, the effect of the interplay between magnetization and the property of the topological insulator surface, otherwise known as spin-momentum locking on the superconducting proximity effect, still remains to be investigated. We relied on the quasiclassical self-consistent approach to consider the superconducting transition temperature in the two-dimensional superconductor/topological insulator (S/TI) junction with an in-plane helical magnetization on the TI surface. It has emerged that the presence of the helical magnetization leads to the nonmonotonic dependence of the critical temperature on the TI thickness for both cases when the magnetization evolves along or perpendicular to the interface. The results obtained can be helpful for designing novel superconducting nanodevices and better understanding the nature of superconductivity in S/TI systems with nonuniform magnetization.

Automated summary

Superconducting hybrid structures with topological order and induced magnetization show potential for fault-tolerant quantum computation. However, the interplay between magnetization and topological insulator surface properties, known as spin-momentum locking, on the superconducting proximity effect needs further investigation. Results from studying a 2D superconductor/topological insulator junction with helical magnetization on the topological insulator surface show nonmonotonic dependence of critical temperature on thickness, whether the magnetization evolves along or perpendicular to the interface. These findings are valuable for designing novel superconducting nanodevices and understanding superconductivity in systems with nonuniform magnetization.