Nonlocal electromagnetic response of graphene nanostructures

Abstract

Nonlocal electromagnetic effects of graphene arise from its naturally dispersive dielectric response. We present semianalytical solutions of nonlocal Maxwell's equations for graphene nanoribbon arrays with features around 100 nm, where we found prominent departures from its local response. Interestingly, the nonlocal corrections are stronger for light polarization parallel to the ribbons, which manifests as an additional broadening of the Drude peak. For the perpendicular polarization case, nonlocal effects lead to blue-shifts of the plasmon peaks. These manifestations provide a physical measure of nonlocal effects, and we quantify their dependence on the ribbon width, doping, and wavelength.

Tunable Terahertz Meta-Surface with Graphene Cut-Wires

“…[53][54][55] For example, intrinsic optical phonons of graphene, scatterings from the edges as well as surface polar phonons in substrate like SiO 2 may lead to a significantly modified plasmon dispersion and damping, edge states may cause a red-shift and broadening of the plasmon resonance in doped graphene nanodisks with zigzag edges, and nonlocal response arised from spatial inhomogeneity will also affect plasmonic resonances in graphene nanostructures. A very recent study also reported the progress in achieving high confinement and low levels of plasmon damping by sandwiching graphene in an exceptionally clean environment with hexagonal boron nitride films.…”

Discontinuous Galerkin Time-Domain Modeling of Graphene Nanoribbon Incorporating the Spatial Dispersion Effects

“…As shown in Fig. 9 and 10, it is noted that the both the real and imaginary parts of the impedance matrix shows a frequency shift and some amplitude variation while the shapes kept similar, which is due to that the nonlocal effects has directly influence on the propagating wave number including the phase constant [19]- [21], thus the relative electric length of the GNR is changed compared with the local model case, which directly results in the variations of the peaks and nulls of the impedance matrix.…”

“…Since the solutions in DGTD method are allowed to be discontinuous at the interface of neighboring domains, the values with superscript * from (19) to (23) are named as numerical flux that are used for communication between adjacent domains in order to guarantee an unique solution.…”

“…Consequently, the effective characteristic impedance of the GNR is dramatically altered [18]- [24]. In [18], the analytical anisotropic Dyadic Green's function method is proposed to handle graphenes over infinitely large substrates while in To analyze a general graphene structure, in [19]- [21], three similar approaches based on the integral equation (IE) method are developed which investigate the dispersion and characteristic impedance of GNRs. As an alternative of full-wave method, the equivalent circuit representation schemes [23]- [25] have been proposed to investigate the effects of the nonlocality with the help of TE and TM transverse resonance method.…”

Graphene Plasmonics: A Platform for 2D Optics

“…[12] Graphene also has been extensively investigated aiming toward potential applications in advanced photonics. [13][14][15][16][17] Graphene supports stronger bonding of surface plasmons, [18][19][20][21][22][23][24][25][26][27][28][29] and the Dirac fermions provides large tunabilities in optical response via magnetic field, electrostatic field, and doping in ultra-wide bands. [30][31][32][33] Compared to the conventional plasmonic materials-noble metals, the plasmonic resonance of graphene resides in the technically important bands: terahertz and infrared frequencies.…”