Ferroelectric tuning of superconductivity and band topology in a two-dimensional heterobilayer

TL;DR

This paper predicts that in a 2D heterobilayer of IrTe2 on ferroelectric In2Se3, both superconductivity and band topology can be reversibly tuned by controlling the ferroelectric polarization, enabling advanced quantum device applications.

Contribution

It introduces the first theoretical prediction of simultaneous tunability of superconductivity and band topology in a 2D heterobilayer via ferroelectric polarization control.

Findings

Superconducting transition temperature (Tc) is significantly enhanced due to charge redistribution.

Tc depends sensitively on In2Se3 polarization, reaching 8-10 K with downward polarization.

Band topology switches from trivial to nontrivial when polarization is reversed.

Abstract

Realization of tunable superconductivity with concomitant nontrivial band topology is conceptually intriguing and highly desirable for superconducting devices and topological quantum computation. Based on first-principles calculations, here we present the first prediction of simultaneously tunable superconducting transition temperature (Tc) and band topology in a superconducting IrTe2 overlayer on a ferroelectric In2Se3 monolayer. We first demonstrate that the Tc is substantially enhanced from that of IrTe2 nanoflakes (Tc ~3 K) due to significant charge repartitioning around the Fermi level. More importantly, the Tc is shown to sensitively depend on the In2Se3 polarization, with the higher Tc of ~(8-10) K attributed to enhanced interlayer electron-phonon coupling when the polarization is downward. The band topology is also switched from trivial to nontrivial as the polarization is reversed from upward to downward. These findings provide physically realistic platforms for simultaneously tuning superconductivity and band topology in two-dimensional heterobilayers and related heterostructures using a reversible and nonvolatile approach.