Theory of the Near-Field Electrostatic Effects in 2D Materials and van der Waals Heterostructures

Two-dimensional (2D) materials have demonstrated a wealth of intrinsic as well as exotic electronic properties arising from near-field electrostatic interactions between layers and from surface organic absorbates, such as emergent ferroelectric order, excitonic energy landscape, and moiré superlattices.<br/>In this work, we derive an analytical theory for such near-field electrostatic effects, and validate it through first-principles calculations[1-2]. We demonstrate that superlattice potentials can be obtained in both 2D-2D and mixed-dimensional organic-2D heterostructures. We develop a classical electrostatic model of the superlattice potentials beyond the multipole expansion. Our theory quantitatively captures the out-of-plane decay and in-plane modulation, as well as elucidates the impacts of geometric effects, structural distortions, and material polarity on the electrostatic potentials.<br/>Finally, we demonstrate the applicability of this theory on efficient prediction of the material-/angle-specific moiré potentials with periodicities challenging for DFT calculations, and band structure engineering for 2D materials by the near-field electrostatic effects.<br/>[1] Q. Zhou, A. Bukuru, S. Trevor, K. Michele, and P. Darancet. <i>arXiv:2109.09990</i> (2021).<br/>[2] Q. Zhou, K. Michele, and P. Darancet. <i>arXiv:2205.04606</i> (2022).