Comparing the image potentials for intercalated graphene with a two-dimensional electron gas with and without a gated grating

Abstract

We calculate the surface response function and the image potential of a system of layered two-dimensional ͑2D͒ electron gas structures. A point charge is placed at a distance away from the surface which lies in the xyplane. These 2D layers are coupled through the Coulomb interaction and there is no interlayer electron hopping. The separation between adjacent layers can be adjusted to investigate the roles which the layer separation and the number of layers play on both the surface response function and the image potential. Specifically, we consider the system composed of graphene layers or the layered 2D electron gas ͑EG͒ formed at the interface of a semiconductor heterostructure such as GaAs/AlGaAs. We show that the image potential for graphene is qualitatively the same as for the 2DEG. We examine the way in which the image potential is modified by applying a one-dimensional periodic electrostatic potential ͑through a gated grating for modula-tion͒. The results indicate that the charge screening for graphene is not much different from the 2DEG.

Dynamic polarization of graphene by moving external charges: Random phase approximation

“…(7) and (8) would simply amount to a shift of the z 0 coordinate by a distance on the order of the lattice constant, which is sometimes referred to as an effective image plane. 34,57 We therefore …”

Strongly Localized Image States of Spherical Graphitic Particles

“…Additionally, these states have been observed for pyrolytic graphite [ 18 ] and metal-supported graphene [ 19 ]. Silkin et al [ 20 ] further highlighted the importance of image states in graphene [ 21 ] by concluding that the interlayer state in graphite is formed by the hybridization of the lowest image-potential state in graphene in a similar way as it occurs in bilayer graphene [ 22 , 23 ]. The significance of image states was also discussed by Rinke et al in [ 24 ].…”

Image potential states in graphene

“…In this case the odd-even symmetry will be broken and the concave surface states will be stabilized with respect to the convex. 12 Finally, the image potential can be modified by an applied gate voltage sufficiently close to the layer 24,[29][30][31] or by the electric field induced by an STM tip. 28,32,33 The following picture can be gleaned from the present results.…”