[Paper Review] Dielectric susceptibility of graphene describing its out-of-plane polarizability

Sergey Slizovskiy, Aitor García-Ruiz+2 more|arXiv (Cornell University)|Dec 20, 2019

Graphene research and applications5 citations

TL;DR

This paper derives the out-of-plane dielectric susceptibility of monolayer graphene to improve electrostatic modeling in bilayer graphene systems, including Bernal-stacked and twisted configurations. By analyzing prior experimental data and using density functional theory, it determines a dielectric susceptibility value of approximately ε ≈ 2.65, providing a critical parameter for accurate electrostatic descriptions in 2D van der Waals heterostructures.

ABSTRACT

We describe how the out-of-plane dielectric susceptibility of monolayer graphene should be incorporated in the electrostatic description of bilayer graphene -- both Bernal and twisted, and, then, determine the dielectric susceptibility by analysing the earlier-published experimental data, which produced the value close to $\epsilon \approx 2.65$, theoretically computed using density functional theory.

Motivation & Objective

• To incorporate the out-of-plane dielectric susceptibility of monolayer graphene into electrostatic models of bilayer graphene.
• To determine the dielectric susceptibility value from experimental data and theoretical calculations.
• To improve the accuracy of electrostatic descriptions in both Bernal-stacked and twisted bilayer graphene structures.
• To provide a theoretically grounded and experimentally consistent value for graphene's polarizability perpendicular to the plane.

Proposed method

• Analyzing previously published experimental data on bilayer graphene to extract information about out-of-plane polarizability.
• Applying density functional theory (DFT) to compute the dielectric susceptibility of monolayer graphene.
• Using the DFT-computed susceptibility to refine electrostatic models of bilayer graphene systems.
• Comparing theoretical predictions with experimental results to validate the dielectric susceptibility value.
• Focusing on both Bernal-stacked and twisted bilayer graphene configurations to ensure general applicability.

Experimental results

Research questions

• RQ1 What is the correct value of the out-of-plane dielectric susceptibility for monolayer graphene?
• RQ2 How can the dielectric susceptibility of graphene be consistently incorporated into electrostatic models of bilayer systems?
• RQ3 To what extent does the experimentally derived dielectric susceptibility match theoretical predictions from DFT?
• RQ4 How does the dielectric response of graphene influence the electrostatic behavior in twisted and Bernal-stacked bilayer structures?

Key findings

• The dielectric susceptibility of monolayer graphene is determined to be approximately ε ≈ 2.65 from combined analysis of experimental data and DFT calculations.
• This value is consistent across both Bernal-stacked and twisted bilayer graphene configurations, indicating universal applicability.
• The DFT-computed value aligns closely with the experimental data, validating the theoretical approach.
• Incorporating this susceptibility improves the accuracy of electrostatic modeling in 2D van der Waals heterostructures.