Sliding Ferroelectrics Induced Hybrid-Order Topological Phase Transitions

Abstract

We propose ferroelectric layer sliding as a new approach to realize and manipulate topological quantum states in two-dimensional (2D) bilayer magnetic van der Waals materials. We show that stacking monolayer ferromagnetic topological states into layer-spin-locked bilayer antiferromagnetic structures, and introducing sliding ferroelectricity leads to asynchronous topological evolution of different layers (spins) owing to existence of polarization potentials, thereby giving rise to rich layer-resolved topological phases. As a specific example, by means of a lattice model, we show that a bilayer magnetic 2D second order topological insulator (SOTI) reveals an unrecognized spin-hybrid-order topological insulator after undergoing ferroelectric sliding. Interestingly, in such phase, the spin-up (top layer) and spin-down (bottom layer) channels exhibit first-order and second-order topological properties, respectively. Moreover, other topological phases such as SOTI, quantum spin Hall insulator, quantum anomalous Hall insulator, and trivial insulator can also emerge through changes in the parameters of the system, and the relevant topological indices are also discussed. In terms of materials, based on first principles calculations, we predict material ScI2 can serve as an ideal platform to realize our proposal. Further, we predict that the anomalous Nernst effect of these several topological phases exhibits distinct differences, and therefore can be used as a signal for experimentally probing.

6 pages, 5 figures

References in corpus (8)

• Topological Crystalline Insulators
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Cited by in corpus (6)

• Sliding Ferroelectricity Induced and Switched Altermagnetism in GaSe-VPSe3-GaSe Sandwiched Heterostructure with Strong Magnetoelectric Effect
• Unconventional hybrid-order topological insulators
• Engineering Two-Dimensional Hybrid-Order Topological Insulators via Trilayer Coupling
• Current switching behavior mediated via hinge modes in higher-order topological phases using altermagnets
• Stabilization of sliding ferroelectricity through exciton condensation
• Ferroelectrically Controlled Chirality Switching of Weyl Quasiparticles