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arXiv · 2303.18124

In-plane flexoelectricity in two-dimensional $D_{3d}$ crystals

Matteo Springolo·Miquel Royo·Massimiliano Stengel
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Abstract

We predict a large in-plane polarization response to bending in a broad class of trigonal two-dimensional crystals. We define and compute the relevant flexoelectric coefficients from first principles as linear-response properties of the undistorted layer, by using the primitive crystal cell. The ensuing response (evaluated for SnS$_{2}$, silicene, phosphorene and RhI$_{3}$ monolayers and for a hexagonal BN bilayer) is up to one order of magnitude larger than the out-of-plane components in the same material. We illustrate the topological implications of our findings by calculating the polarization textures that are associated with a variety of rippled and bent structures. We also determine the longitudinal electric fields induced by a flexural phonon at leading order in amplitude and momentum.

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Matteo Springolo, Miquel Royo, Massimiliano Stengel. 2023-03-31. In-plane flexoelectricity in two-dimensional $D_{3d}$ crystals. https://arxiv.org/abs/2303.18124

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