Effect of Temperature and Doping on Plasmon Excitations for an Encapsulated Double‐Layer Graphene Heterostructure

Abstract

We perform a comprehensive analysis of the spectrum of graphene plasmons which arise when a pair of sheets are confined between conducting materials. The associated enhanced local fields may be employed in the manipulation of light on the nanoscale by adjusting the separation between the graphene layers, the energy band gap as well as the concentration of charge carriers in the conducting media surrounding the two-dimensional (2D) layers. We present a theoretical formalism, based on the calculation of the surface response function, for determining the plasmon spectrum of an encapsulated pair of 2D layers and apply it to graphene. We solve the coupled equations involving the continuity of the electric potential and discontinuity of the electric field at the interfaces separating the constituents of the hybrid structure. We have compared the plasmon modes for encapsulated gapped and gapless graphene. The associated nonlocal graphene plasmon spectrum coupled to the "sandwich" system show a linear acoustic plasmon mode as well as a low-frequency mode corresponding to in-phase oscillations of the adjacent 2D charge densities. These calculations are relevant to the study of energy transfer via plasmon excitations when graphene is confined by a pair of thick conducting materials.

Effect of strain on plasmons, screening, and energy loss in graphene/substrate contacts

“…where a i , b i are determined using the electrostatic conditions at the boundaries separating the regions. 35 After a straightforward calculation, we obtain the coefficients for the potential in the region −d 1 ≤ z ≤ 0 as…”

“…The method of calculation was based on the formalism presented by previous authors 29,30 who considered a 2D layer and cylindrical nanotube interacting with a beam of impinging charged particles. However, in recent work, Woessner, et al 31,32 released experimental and theoretical results for plasmon excitations in a heterostructure of graphene which is encapsulated [33][34][35] between two films of hexagonal boron-nitride using a method that exploits near-field-microscopy. The collective mode spectrum revealed in the experimental data of Refs.…”

“…Ref. [35], involving the electrostatic potential, electric field and the induced charge density at the interfaces of the structure shown in Fig. 1.…”

Plasmon damping rates in Coulomb-coupled two-dimensional layers in a heterostructure

“…al. 49,50 which gives us the condition for the existence of the plasmon dispersion. The analytical result for the surface response function is further used for different limiting cases and a comprehensive comparison is made with a variety of structures composed of different graphene-silicene compositions.…”

Coulomb drag in metal monochalcogenides double-layer structures with Mexican-hat band dispersions

“…In addition, successfully synthesizing monolayer and few-layer MXs, including GaS, GaSe and InSe, presents an intriguing opportunities for future semiconductor technology [20][21][22][23]. * t-vazifeh@sbu.ac.ir Over the course of past few decades, a great deal of attention has focused on double-layer 2D structures because of their interesting many-body and transport features which arise from the inter-layer Coulomb interaction between the two parallel electron or hole systems that are coupled in close proximity [24][25][26][27][28]. The Coulomb drag phenomenon provides an opportunity to measure the effects of electron-electron interactions through the transport measurement, directly where the momentum is transferred from one layer to the other layer due to the inter-layer Coulomb coupling [29][30][31][32].…”