Edge State Quantum Interference in Twisted Graphitic Interfaces

Abstract

Zigzag edges in graphitic systems exhibit localized electronic states that drastically affect their properties. Here, room-temperature charge transport experiments across a single graphitic interface are reported, in which the interlayer current is confined to the contact edges. It is shown that the current exhibits pronounced oscillations of up to ≈40 μA with a dominant period of ≈5 Å with respect to lateral displacement that do not directly correspond to typical graphene lattice spacing. The origin of these features is computationally rationalized as quantum mechanical interference of localized edge states showing significant amplitude and interlayer coupling variations as a function of the interface stacking configuration. Such interference effects may therefore dominate the transport properties of low-dimensional graphitic interfaces.

The Driven Liouville von Neumann Approach to Electron Dynamics in Open Quantum Systems

“…[155,159] More recently, a spin-compensated TDDFT implementation of the DLvN approach that imposes open boundary conditions via the site-to-state transformation was presented. [160] While being more computationally demanding, it was found to conserve both Pauli's exclusion principle and density matrix positivity within a numerically stable scheme. First, the current dynamics of a simplified hydrogen chain model was investigated, demonstrating how current density variations can be explored using the developed approach (Figure 7).…”

“…The border lines between the extended molecule section and the source and sink driven leads are located at �10:3 Å, and the seam lines between the weakly coupled molecule and the left and right segments of the EM are located at �1:2 Å, as marked by the vertical black dashed lines. Adapted with permission from Ref [160]…”