Optical Studies of Ordered Monomolecular Layers: Ab Initio Simulation and Experiment

Due to the general interest on the alignment effect of the surface-bound ultrathin layers, this thesis presents research of the investigation of anchoring properties for liquid crystal (LC) molecules adsorbed on a solid substrate, using dual polarization interferometry (DPI). A new theoretical framework is designed based on the dual polarization interferometer for the detection of anisotropic information and the average anchoring angle of the adsorbed molecules, provided the liquid crystal bulk optogeometric parameters are well known. In the experiment, the nematic compound 4'-n-pentyl-4- cyanobiphenyl (5CB) is applied onto the silicon oxynitride surface, and a complete wetting monolayer with the average 56 ° polar angle and 16.6 Å thickness is observed in the stabilized stage. The results match quite well with the theoretical predictions in terms of the DPI phase change ratio. The thesis also extends the research into the functionalized substrate, in particular the Langmuir-Blodgett (LB) films covered substrate, which can give alignment effect to the deposited LC molecules. The LB forming molecule quinolinium tricyanoquinodimethanide (Q3CNQ) with long hydrocarbon chain (typically C18H37-Q3CNQ) is chosen. In order to justify the functionality of this material as an alignment layer, the electronic structure and the optical absorptive properties of this molecule in the LB phase are explored both in experiment and theory. Based on the very controversial history of this Q3CNQ compound, a robust computational LB model is built to examine the ground state, optimal geometry and the optical absorption features. A 530 nm absorption band is obtained to conclude the properties of the Q3CNQ LB layers, and also used to compare with our own experimental results

Grid-based methods for chemistry simulations on a quantum computer

First-quantized, grid-based methods for chemistry modeling are a natural and elegant fit for quantum computers. However, it is infeasible to use today’s quantum prototypes to explore the power of this approach because it requires a substantial number of near-perfect qubits. Here, we use exactly emulated quantum computers with up to 36 qubits to execute deep yet resource-frugal algorithms that model 2D and 3D atoms with single and paired particles. A range of tasks is explored, from ground state preparation and energy estimation to the dynamics of scattering and ionization; we evaluate various methods within the split-operator QFT (SO-QFT) Hamiltonian simulation paradigm, including protocols previously described in theoretical papers and our own techniques. While we identify certain restrictions and caveats, generally, the grid-based method is found to perform very well; our results are consistent with the view that first-quantized paradigms will be dominant from the early fault-tolerant quantum computing era onward

Electromagnetic Waves

This book is dedicated to various aspects of electromagnetic wave theory and its applications in science and technology. The covered topics include the fundamental physics of electromagnetic waves, theory of electromagnetic wave propagation and scattering, methods of computational analysis, material characterization, electromagnetic properties of plasma, analysis and applications of periodic structures and waveguide components, and finally, the biological effects and medical applications of electromagnetic fields

Gratings: Theory and Numeric Applications

International audienceThe book containes 11 chapters written by an international team of specialist in electromagnetic theory, numerical methods for modelling of light diffraction by periodic structures having one-, two-, or three-dimensional periodicity, and aiming numerous applications in many classical domains like optical engineering, spectroscopy, and optical telecommunications, together with newly born fields such as photonics, plasmonics, photovoltaics, metamaterials studies, cloaking, negative refraction, and super-lensing. Each chapter presents in detail a specific theoretical method aiming to a direct numerical application by university and industrial researchers and engineers