Nonvolatile ferroelectric control of topological states in 2D heterostructures

TL;DR

This paper demonstrates a nonvolatile, electrically controlled method to switch topological states in 2D heterostructures using ferroelectric polarization reversal, advancing nanoscale electronic applications.

Contribution

It introduces a novel ferroelectric control mechanism for topological states in 2D heterostructures based on first-principles calculations.

Findings

Switchable topological states in Bi(111) and {\

}In2Se3 heterostructures

Topological switching driven by ferroelectric polarization reversal,

Abstract

Quantum spin Hall (QSH) insulator materials feature topologically protected edge states that can drastically reduce dissipation and are useful for the next-generation electronics. However, the nonvolatile control of topological edge state is still a challenge. In this paper, based on first-principles calculations, the switchable topological states are found in the van der Waals (vdW) heterostructures consisting of two dimensional (2D) Bi(111) bilayer (BL) and {\alpha}-In2Se3 by reversing the electric polarization of the ferroelectric {\alpha}-In2Se3. The topological switching results from the different charge transfer associated with the two opposite polarization states of {\alpha}-In2Se3. This new topological switching mechanism has the unique advantages of being fully electrical as well as nonvolatile. Our finding provides an unprecedented approach to realize ferroelectric control of topological states in 2D materials, which will have great potential for applications in topological nanoscale electronics.