A new modeling formalism to compute the timedependent behavior of combined electromagnetic (EM) and quantum mechanical (QM) systems is proposed. The method is geared towards highly multiscale geometries, which is vital for the future design of nanoelectronic devices. The advocated multiphysics modeling formalism leverages the alternating-direction hybrid implicit-explicit (ADHIE) finite-difference time-domain (FDTD) method for the EM fields and is combined with a novel ADHIE method for the EM potentials. Additionally, we tackle the QM problem using a new split real and imaginary part formulation that includes higher-order spatial differences and arbitrary timedependent EM potentials. The validity of the proposed formalism is theoretically discussed by deriving its stability condition and calculating the numerical dispersion relation. Furthermore, the applicability of our modeling approach is proven through several numerical experiments, including a single-particle Maxwell-Schrödinger (MS) system as well as a many-particle Maxwell-Kohn-Sham (MKS) system within the time-dependent density-functional theory (TDDFT) framework. These experiments confirm that the novel ADHIE method drastically decreases the computation time while retaining the accuracy, leading to efficient and accurate simulations of light-matter interactions in multiscale nanoelectronic devices.
The influence of barrier thickness variability on the charge transfer characteristics of an InP/InAs/InP nanowire resonant-tunneling diode is studied. The transmission probability through the diode is calculated by solving the timedependent effective-mass Schrödinger equation with the Alternating-Direction Hybrid Implicit-Explicit (ADHIE) Finite-Difference Time-Domain (FDTD) method. This recently developed method is tailored towards multiscale problems and thus allows for a much faster evaluation of the transmission probability compared to the commonly used leapfrog FDTD method. Accurate and efficient modeling of small geometric features with the ADHIE-FDTD method now facilitates the development of a robust Monte Carlo method to assess the significant influence of the thickness of the barriers on the transmission probability and the current-voltage characteristic.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.