Simulation of three-dimensional nanoscale light interaction with spatially dispersive metals using a high order curvilinear DGTD method

• Published in: Journal of computational physics Vol. 373; pp. 210 - 229
• Main Authors: Schmitt, Nikolai, Scheid, Claire, Viquerat, Jonathan, Lanteri, Stéphane
• Format: Journal Article
• Language: English
• Published: Cambridge Elsevier Inc 15.11.2018; Elsevier Science Ltd; Elsevier
• Subjects: Computational physics; Computer Science; Computer simulation; Discontinuous Galerkin time-domain method; Electromagnetic radiation; Fluxes; Galerkin method; Isoparametric curvilinear elements; Mathematical models; Maxwell's equations; Modeling and Simulation; Nanoparticles; Nanoplasmonics; Nonlocal Drude model; Runge-Kutta method; Simulation; Spatial dispersion; Stability analysis; Time domain analysis; Wave propagation; Discontinuous Galerkin time-domain method; Nanoplasmonics; Maxwell's equations; Nonlocal Drude model; Spatial dispersion; Isoparametric curvilinear elements
• ISSN: 0021-9991; 1090-2716
• DOI: 10.1016/j.jcp.2018.06.033

•An improved time-domain material model for spatially dispersive materials.•The model combines a local dispersion model for the bound electrons with a nonlocal one for the free electrons response.•Performance improvements of DGTD due to upwind fluxes, curvilinear meshes, and parallel computing in 3D.•First demonstration of strong resonance blue shifts in the absorption spectra of a single nanocube, caused by spatial dispersion. In this work, we present and study a flexible and accurate numerical solver in the context of three-dimensional computational nanophotonics. More precisely, we focus on the propagation of electromagnetic waves through metallic media described by a non-local dispersive model. For this model, we propose a discretization based on a high-order Discontinuous Galerkin time-domain method, along with a low-storage Runge–Kutta time scheme of order four. The semi-discrete stability of the scheme is analyzed for classical numerical fluxes, i.e. centered and upwind. Furthermore, the numerical treatment is enriched with an enhanced approximation of the geometry based on isoparametric curvilinear meshes. We finally assess our approach on several test cases, from academic to more physical ones.