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arXiv · 2309.00728

Quantum-Geometric Origin of Out-of-plane Stacking Ferroelectricity

Benjamin T. Zhou·Vedangi Pathak·Marcel Franz
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Abstract

Stacking ferroelectricity (SFE) has been discovered in a wide range of van der Waals materials and holds promise for applications, including photovoltaics and high-density memory devices. We show that the microscopic origin of out-of-plane stacking ferroelectric polarization can be generally understood as a consequence of nontrivial Berry phase borne out of an effective Su-Schrieffer-Heeger model description with broken sublattice symmetry, thus elucidating the quantum-geometric origin of polarization in the extremely non-periodic bilayer limit. Our theory applies to known stacking ferroelectrics such as bilayer transition-metal dichalcogenides in 3R and T$_{\rm d}$ phases, as well as general AB-stacked honeycomb bilayers with staggered sublattice potential. Our explanatory and self-consistent framework based on the quantum-geometric perspective establishes quantitative understanding of out-of-plane SFE materials beyond symmetry principles.

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Benjamin T. Zhou, Vedangi Pathak, Marcel Franz. 2023-09-01. Quantum-Geometric Origin of Out-of-plane Stacking Ferroelectricity. https://doi.org/10.1103/physrevlett.132.196801

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