The potential for fast van der Waals computations for layered materials using a Lifshitz model

Abstract

Computation of the van der Waals (vdW) interactions plays a crucial role in the study of layered materials. The adiabatic-connection fluctuation-dissipation theorem within random phase approximation (ACFDT-RPA) has been empirically reported to be the most accurate of commonly used methods, but it is limited to small systems due to its computational complexity. Without a computationally tractable vdW correction, fictitious strains are often introduced in the study of multilayer heterostructures, which, we find, can change the vdW binding energy by as much as 15%. In this work, we employed for the first time a defined Lifshitz model to provide the vdW potentials for a spectrum of layered materials orders of magnitude faster than the ACFDT-RPA for representative layered material structures. We find that a suitably defined Lifshitz model gives the correlation component of the binding energy to within 8-20% of the ACFDT-RPA calculations for a variety of layered heterostructures. Using this fast Lifshitz model, we studied the vdW binding properties of 210 three-layered heterostructures. Our results demonstrate that the three-body vdW effects are generally small (10% of the binding energy) in layered materials for most cases, and that non-negligible second-nearest neighbor layer interaction and three-body effects are observed for only those cases in which the middle layer is atomically thin (e.g. BN or graphene). We find that there is potential for particular combinations of stacked layers to exhibit repulsive three-body van der Waals effects, although these effects are likely to be much smaller than two-body effects.

Dynamic Optical Tuning of Interlayer Interactions in the Transition Metal Dichalcogenides

“…The Casimir interaction represents a special case of this theory valid for the limit of large l and perfect metal slabs. In the limit of small spacing between two plates, the effective pressure predicted by this theory can be written as where ε is the frequency dependent dielectric function evaluated at complex values, ℏ is the reduced Planck constant, and the integral is over all frequencies. , Although this model is not intended to be accurate for atomic scale separations, comparison with more detailed models based on electronic structure calculations suggests that it captures the essential physics of the response for some semiconducting 2D materials . As a simple approximation to simulate our experimental conditions, we assume a Drude model for the dielectric function, , where ω p is the plasma frequency (proportional to the square root of the photoexcited carrier density n ), and γ is the Drude damping term.…”

“…9,12 Although this model is not intended to be accurate for atomic scale separations, comparison with more detailed models based on electronic structure calculations suggests that it captures the essential physics of the response for some semiconducting 2D materials. 31 As a simple approximation to simulate our experimental conditions, we assume a Drude model for the dielectric function,…”

High‐throughput computational screening of layered and two‐dimensional materials

“…To deal with this issue, there are several kinds of currently applied dispersion corrections in DFT: 58 parameterized density functionals (DFs), nonlocal vdW-DFs, 59 DFT-D methods, [60][61][62] and effective one-electron potentials, named dispersion-correcting potentials (DCPs). 63 Moreover, the random-phase approximation (RPA) 64,65 was also widely applied in the computation of vdW interactions and empirically reported to be the most accurate among the commonly used methods. However, due to its computational complexity, RPA was generally used in small systems.…”

Solid-State Lifshitz-van der Waals Repulsion through Two-Dimensional Materials

“…m and m = ⟂ m ∕ ∥ m are the geometricallyaveraged dielectric function and dielectric anisotropy 33 of m, respectively. Similar approach was also used to calculate vdW interactions of layered materials 34 . Δ Am and Δ Bm correspond to the dielectric mismatches…”

“…AmB , but also an attractive potential, Φ Att , corresponding to the two-body vdW potential between gold and graphene, Φ vdW mB 30,34 . The total potential acting on gold, Φ tot = Φ Att + Φ Rep , combines both effects.…”