Large graphene-induced shift of surface-plasmon resonances of gold films: Effective-medium theory for atomically thin materials

Abstract

Despite successful modeling of graphene as a 0.34-nm thick optical film synthesized by exfoliation or chemical vapor deposition (CVD), graphene induced shift of surface plasmon resonance (SPR) of gold films has remained controversial. Here we report the resolution of this controversy by developing a clean CVD graphene transfer method and extending Maxwell-Garnet effective medium theory (EMT) to 2D materials. A SPR shift of 0.24º is obtained and it agrees well with 2D EMT in which wrinkled graphene is treated as a 3-nm graphene/air layered composite, in agreement with the average roughness measured by atomic force microscope. Because the anisotropic built-in boundary condition of 2D EMT is compatible with graphene's optical anisotropy, graphene can be modelled as a film thicker than 0.34-nm without changing its optical property; however, its actual roughness, i.e., effective thickness will significantly alter its response to strong out-of-plane fields, leading to a larger SPR shift.

Surface plasmon resonance based on graphene-metal-graphene structure: recurrence relation theory

“…Equation ( 12) also shows how a graphene induces a shift of surface-plasmon resonances of metal films, which agrees with the experimental results reported in Ref. [14].…”

“…Therefore, these excellent properties make graphene a favorable candidate for novel plasmonic devices and potential applications in photonics, optoelectronics, and in sensor technologies [8]. Hence, the hybridization of graphene-metal metamaterials plays an important role in the field of plasmonics and exploring the interactions of the plasmon modes in multilayer graphene structures coupled via Coulomb interaction with metallic substrates offer new opportunities for applications and fundamental studies of collective electron excitations in plasmonic metamaterials for biological and chemical sensing [9][10][11][12][13][14][15][16][17], photodetectors [18] and optoelectronics [19,20].…”

Nonlocal effective-medium theory for periodic multilayered metamaterials

“…Physically, LEMT breaks down close to the TIR angle because the waves become evanescent in the low-index layers but remain propagating in the high-index layers [19,20]. We note that the origin of this breakdown phenomenon is related to the spatial-dispersion nonlocal effects [34,35], whereas LEMT does not capture this physics [21][22][23][36][37][38].…”

Tailoring Group Delay Dispersion of Spatial Phaser using Anisotropic Metasurface and Polarized Incident Waves

“…This mixed substrates is anisotropic since its effective permittivity depends on the polarization of incidence. [ 37 ] From the fundamental definition of permittivity, it is known that ϵ eff = D / E , where D is the average electric flux density and E denotes an average intensity of electric field. From the boundary conditions of Maxwell's equations, it is further known that, at an interface of two different materials, parallel component of E , and perpendicular component of D , are continuous, shown in Figure 2b.…”