Understanding and engineering non-covalent van der Waals (vdW) interactions at 2D material interfaces are critical for a large varieties of applications, including molecular epitaxy, self-assembly, wetting properties and vdW heterostructure formation. When two macroscopic bodies are separated by a 2D material, classical pair-wise theory predicts effective penetration of vdW interactions through the few-atom thick 2D layer, leading to phenomena such as wetting transparency. However, such simple picture is challenged by recent experimental advances. Here we present a more precise theoretical analysis, combining modern many-body theory of vdW interactions with fundamental electronic structure of 2D materials, to resolve this controversy. By quantifying the frequency-dependent vdW “transparency”, we show that 2D materials act as high-pass filter of vdW interactions which selectively screen low frequency range interactions (such as Keesom and Debye interactions) due to their highly anisotropic dielectric nature. Such partial transmission of vdW interaction is highly nonlinear, depending primarily on the bandgaps of materials and the spacing between macroscopic bodies. Using the theoretical model, we successfully explain the experimental observation of screened vdW interaction through 2D materials, which is further endorsed by high level <i>ab initio</i> simulations. Moreover, our model provides an effective approach for high-throughput study on over 10<sup>5</sup> combinations of bulk and 2D materials, enabling the finding of systems with negative (repulsive) and over-unity (enhanced) vdW transparencies. Our findings reveal the mighty potential of using 2D materials to engineer the interfacial vdW interactions, as well as fundamental insights into the underlying physics.

Two-dimensional materials as high-pass filter of van der Waals interactions

2019 Fall National Meeting

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