Nonlocal plasma spectrum of graphene interacting with a thick conductor

Abstract

Self-consistent field theory is used to obtain the non-local plasmon dispersion relation of monolayer graphene which is Coulomb-coupled to a thick conductor. We calculate numerically the undamped plasmon excitation spectrum for arbitrary wave number. For gapped graphene, both the lowfrequency (acoustic) and high frequency (surface) plasmons may lie within an undamped opening in the particle-hole region. Furthermore, we obtain plasmon excitations in a region of frequency-wave vector space which do not exist for free-standing gapped graphene.

Tunable surface plasmon instability leading to emission of radiation

“…The proper mathematical formalism to include the surface plasmon interacting with a 2D layer was first presented by Horing et al 20 Detailed numerical investigation of the plasmon excitation for such systems demonstrated the extended regions of undamped plasmons. 50 In addition, the work reported by Mikhailov 29 on voltage-tunable THz emitter relies on a structure to perform a periodic spatial modulation to the velocity of an incident electron beam. This modulation can be realized by introducing a biased metallic grating adjacent to the electron beam.…”

Controlling plasmon modes and damping in buckled two-dimensional material open systems

“…(17), the linear dispersions and their prefactor scalings are the same as those for graphene. 68 However, the two independent bandgaps, ∆ SO and ∆ z , play unique roles in shaping the hybrid-plasmon branches when the damping from different PHMs is considered. It is found that the outer PHM's boundaries are only determined by ∆ < and the two hybrid-plasmon group velocities (slopes) are proportional to G and √ G. These two group velocities drop to zero as ∆ SO and ∆ z increase since G 4 √ 2αv…”

“…68,[73][74][75][76] Furthermore, our previous work studied the plasmon instability in the graphene double-layer system, predicting an instability-based terahertz emission, 77 and nonlocal plasmons in a metal-graphene-metal encapsulated structure.…”

“…The most distinguished feature of such an open system is the dynamically-screened Coulomb interaction between electrons in graphene and the conducting substrate. 68 Screening is included by calculating the nonlocal frequency-dependent inverse dielectric function K(r, r ; ω) which is related to the regular dielectric function (r, r ; ω) by d 3 r K(r, r ; ω) (r , r ; ω) = δ(r − r ). The resonance occurring in K(r, r ; ω) corresponds to the nonlocal plasmon modes.…”

Adatom doping-enriched geometric and electronic properties of pristine graphene: a method to modify the band gap

“…Creating pristine graphene in commercial quantities with a specific band gap is a major challenge in its use for nanoelectronic devices. Some of the intriguing properties which have received a great deal of attention include the doping and temperature dependence of plasmon excitations and their energy dispersion dependence on the direction of the wave vector in the Brillouin zone for graphene [10][11][12][13][14][15], the Klein paradox [16][17][18][19], the Veselago lens [19][20][21], screened impurity potential [22,23], effect of magnetic field [22] to name just a few.…”