1,721,141 research outputs found
Analysis and characterization of nano-scale devices based on new low dimensional materials
No full text
Full-wave techniques for the multi-physics modeling and design of nano-structured devices
No full textFull-wave multiphysics techniques aimed at the investigation of the
combined electromagnetic-coherent transport phenomena in carbonbased
nano-structures/devices are presented.
Advanced numerical tools, in the frequency (energy)-domain and timedomain
and in multi-scale environment are derived. The quantum
transport is modeled by i) discrete Hamiltonians at atomistic scale, ii)
Schrödinger equation, and/or Dirac/Dirac-like eqs. at continuous level.
In the frequency-domain, a rigorous Poisson-coherent transport equation
system is provide
Analysis of Carbon Nanoribbons Devices by Joint Use of Electromagnetic Solvers and Multi-channel Transport Models
No full textMultimode Transverse Resonance of Multilayer Crystal Slabs
No full textAbstract:
An effective tool for accurate analysis and design of a wide range of optical devices involving three-dimensional (3-D) photonic crystals is provided. The advantages of using transverse resonance in conjunction with full-wave numerical solvers in order to characterize this kind of structures are highlighted. This paper focuses on the study of a practical example of an asymmetric crystal slab and shows the features of the proposed method in terms of accuracy and flexibility. The concept of Floquet modes of a periodic crystal is applied, and a multimode transverse equivalent network is developed in the aim of obtaining the resonant 3-D modes of the slab containing the photonic crysta
Application of algebraic invariants to full-wave simulators - rigorous analysis of the optical properties of nanowires
No full textWe show an application of four states algebraic invariants to the extraction of the main optical properties of anisotropic semiconductor thin nanowires such as the complex propagation constant of the guided modes and the reflectivity at the waveguide terminations. In order to provide a numerical example, we calculate the modal and threshold gains for the first few guided modes. This has been done in conjunction with the use of a full-wave finite-element method simulator without the isotropic approximation of passive GaN. Moreover, the device has been directly analyzed in his active state, i.e., with a complex dielectric tensor: in principle, a rigorous complex resonance for simultaneously calculating the lasing frequency and the threshold gain may be performe
Full-Wave Techniques for the Multiphysics Quantum and Electrodynamics Modeling of Nanodevices
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Scattering matrix approach to multichannel transport in many lead graphene nanoribbons
No full textMultichannel analysis of graphene nanoribbons (GNR), often required for describing applications to practical devices, constitutes a heavy computational task, even in a simplified
framework like that provided by discrete or nearest neighbour models. Scattering (S) matrix techniques, widely used for quantum transport in low dimensional systems and for the
computation of electromagnetic fields, is shown here to provide a powerful formal platform for the analysis, and, in principle, the synthesis, of GNR multiport circuits. Periodic modes,
solutions of GNR waveguides, are demonstrated to obey charge conservation and reciprocity
constraints corresponding to unitary and symmetry properties of the S-matrix, under proper normalization conditions. We propose a systematic use of this approach to deal with problems
such as scattering by lattice defects, the presence of external applied fields, crossing GNRs and T-junction
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