Graphene Electrodynamics in the presence of the Extrinsic Spin Hall Effect

Abstract

We extend the electrodynamics of two dimensional electron gases to account for the extrinsic spin Hall effect (SHE). The theory is applied to doped graphene decorated with a random distribution of absorbates that induce spin-orbit coupling (SOC) by proximity. The formalism extends previous semiclassical treatments of the SHE to the non-local dynamical regime. Within a particle-number conserving approximation, we compute the conductivity, dielectric function, and spin Hall angle in the small frequency and wave vector limit. The spin Hall angle is found to decrease with frequency and wave number, but it remains comparable to its zero-frequency value around the frequency corresponding to the Drude peak. The plasmon dispersion and linewidth are also obtained. The extrinsic SHE affects the plasmon dispersion in the long wavelength limit, but not at large values of the wave number. This result suggests an explanation for the rather similar plasmonic response measured in exfoliated graphene, which does not exhibit the SHE, and graphene grown by chemical vapor deposition, for which a large SHE has been recently reported. Our theory also lays the foundation for future experimental searches of SOC effects in the electrodynamic response of two-dimensional electron gases with SOC disorder.

12 pages, 4 figures

References in corpus (8)

• Graphene plasmonics
• Intrinsic and Rashba Spin-orbit Interactions in Graphene Sheets
• Spin-orbit coupling in curved graphene, fullerenes, nanotubes, and nanotube caps
• Spin Hall Effect
• Spin-orbit coupling in fluorinated graphene
• Long-lived spin plasmons in a spin-polarized two-dimensional electron gas
• Dielectric function, screening, and plasmons of graphene in the presence of spin-orbit interactions
• Extrinsic Spin Hall Effect from Anisotropic Rashba Spin-Orbit Coupling in Graphene

Cited by in corpus (4)

• Direct coupling between charge current and spin polarization by extrinsic mechanisms in graphene
• Valley Hall Effect and Nonlocal Transport in Strained Graphene
• Spin-charge conversion in disordered two-dimensional electron gases lacking inversion symmetry
• Control of Spin Diffusion and Suppression of the Hanle Effect by the Coexistence of Spin and Valley Hall Effects