Enhanced stability and superconductivity of IrTe2/In2Se3 heterobilayers with ferroelectrically switchable band topology

Abstract

Recent advances in realizing ferroelectric and superconducting two-dimensional heterobilayers provide appealing platforms for exploring the interplay between ferroelectricity and superconductivity, which is not only crucial for understanding the superconducting mechanism but also important for designing next-generation superconducting devices. Based on first-principles calculations, we demonstrate that an IrTe2 monolayer can be stabilized on a ferroelectric In2Se3 monolayer via interlayer coupling. The superconducting transition temperature of the IrTe2/In2Se3 heterobilayer is substantially enhanced from that of bulk IrTe2 mainly due to enhanced interlayer coupling, supplemented by the increase in the density of states at the Fermi level and phonon softening; the latter is further tied to Fermi surface nesting. Our calculations show that superconductivity is dominant over several typical competing orders, including charge density wave, magnetism, and nematicity. Moreover, we find that the band topology of IrTe2/In2Se3 can be switched between trivial and nontrivial by reversing the ferroelectric polarization of the In2Se3 substrate. By further substituting Ir with Pd, the topological edge states can be tuned close to the Fermi level, making IrTe2/In2Se3 a potential candidate for realizing topological superconductivity. Our work provides a realistic system that can simultaneously harbor ferroelectricity, superconductivity, and nontrivial band topology, paving the way for integrating multiple applications, such as superconducting field transistors, topological quantum computing, and tunable superconducting diodes, in a single system.

Source-reported materials — not catalogue approval

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