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Design and Fabrication Challenges of Integrated Optical Circuits for Quantum Computing Applications 23

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Design and Fabrication Challenges of Integrated Optical Circ...

23rd International Conference on Transparent Optical Networks, ICTON 2023

作者： Tsintzos, Simeon I. Tsimvrakidis, Konstantinos Sinani, Alexandra Bogris, Adonis Gates, James C. Smith, Peter G.R. Elshaari, Ali W. Zwiller, Val Riziotis, Christos Theoretical & Physical Chemistry Institute National Hellenic Research Foundation Athens11635 Greece University of West Attica Department of Informatics and Computer Engineering Egaleo12243 Greece University of Southampton Optoelectronics Research Centre SouthamptonSO17 1BJ United Kingdom Department of Applied Physics Stockholm106 91 Sweden Institute for Advanced Modelling and Simulation University of Nicosia NicosiaCY-2417 Cyprus

ISBN: (纸本)9798350303032

The paper presents current design issues, limitations, and fabrication challenges towards the development of hybrid integrated optical circuits with embedded single photon sources, which are critical components for future quantum computing, sensing, and communication systems. Optical nanowires with embedded quantum dots (NWQD) are very promising single photon sources, with several reported results of integration in high index platforms like silicon or silicon nitride. Silica on silicon is a favorable platform for optical computing, providing the high degree of customization when combined with direct laser writing techniques for definition of optical structures with refractive index modification. However, the low ~10-3 achievable refractive index contrast imposes strict limitations on the compatibility with NWQD resulting in general in low coupling efficiency as shown in this work. Consideration of several design and fabrication issues demonstrates the potential for NQWD integration in laser written silica based optical circuits with adequate efficiency for practical applications. © 2023 IEEE.

关键词： Fabrication

Generalised tangent stabilised nonlinear elasticity: An automated framework for controlling material and geometric instabilities

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arXiv 2024年

作者： Poya, Roman Ortigosa, Rogelio Gil, Antonio J. Kim, Theodore Bonet, Javier Meshing Framework Simulation & Test Solutions Siemens Digital Industries Software Cambridge United Kingdom Multiphysics Simulation and Optimization Lab Technical University of Cartagena Cartagena Murcia Spain Zienkiewicz Centre for Modelling Data and AI Faculty of Science and Engineering Swansea University Bay Campus United Kingdom Computer Graphics Group Yale School of Engineering & Applied Science Yale University New HavenCT United States Barcelona Spain

Tangent stabilised large strain isotropic elasticity was recently proposed by Poya et al. [1] wherein by working directly with principal stretches the entire eigenstructure of constitutive and geometric/initial stiffness terms were found in closed-form, giving fresh insights into exact convexity conditions of highly non-convex functions in discrete settings. Consequently, owing to these newly found tangent eigenvalues an analytic tangent stabilisation was proposed (for common non-convex strain energies that exhibit material and/or geometric instabilities) bypassing incumbent numerical approaches routinely used in nonlinear finite element analysis. This formulation appears to be extremely robust for quasi-static simulation of complex deformations even with no load increments and time stepping while still capturing instabilities (similar to dynamic analysis) automatically in ways that are infeasible for path-following techniques in practice. In this work, we generalise the notion of tangent stabilised elasticity to virtually all known invariant formulations of nonlinear elasticity. We show that, closed-form eigen-decomposition of tangents is easily available irrespective of invariant formulation or integrity basis. In particular, we work out closed-form tangent eigensystems for isotropic Total Lagrangian deformation gradient (F)-based and right Cauchy-Green (C)-based as well as Updated Lagrangian left Cauchy-Green (b)-based formulations and present their exact convexity conditions postulated in terms of their corresponding tangent and initial stiffness eigenvalues. In addition, we introduce the notion of geometrically stabilised polyconvex large strain elasticity for models that are materially stable but exhibit geometric instabilities for whom we construct their initial stiffness in a spectrally-decomposed form analytically. We further extend this framework to the case of transverse isotropy where once again, closed-form tangent eigensystems are found for common tran

关键词： Stiffness

Using AI libraries for Incompressible Computational Fluid Dynamics

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arXiv 2024年

作者： Chen, Boyang Heaney, Claire E. Pain, Christopher C. Applied Modelling and Computation Group Department of Earth Science and Engineering Imperial College London SW7 2AZ United Kingdom Centre for AI-Physics Modelling Imperial-X Imperial College London W12 7SL United Kingdom Novel Reservoir Modelling and Simulation Group Department of Earth Science and Engineering Imperial College London London United Kingdom Data Assimilation Laboratory Data Science Institute Imperial College London SW7 2AZ United Kingdom

Recently, there has been a huge effort focused on developing highly efficient open source libraries to perform Artificial Intelligence (AI) related computations on different computer architectures (for example, CPUs, GPUs and new AI processors). This has not only made the algorithms based on these libraries highly efficient and portable between different architectures, but also has substantially simplified the entry barrier to develop methods using AI. Here, we present a novel methodology to bring the power of both AI software and hardware into the field of numerical modelling by repurposing AI methods, such as Convolutional Neural Networks (CNNs), for the standard operations required in the field of the numerical solution of Partial Differential Equations (PDEs). The aim of this work is to bring the high performance, architecture agnosticism and ease of use into the field of the numerical solution of PDEs. We use the proposed methodology to solve the advection-diffusion equation, the non-linear Burgers equation and incompressible flow past a bluff body. For the latter, a convolutional neural network is used as a multigrid solver in order to enforce the incompressibility constraint. We show that the presented methodology can solve all these problems using repurposed AI libraries in an efficient way, and presents a new avenue to explore in the development of methods to solve PDEs and Computational Fluid Dynamics problems with implicit methods. © 2024, CC BY.

关键词： Computational fluid dynamics

Probing the unfolded configurations of a β-hairpin using sketch-map

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arXiv 2023年

作者： Ardevol, Albert Tribello, Gareth A. Ceriotti, Michele Parrinello, Michele Computational Science Department of Chemistry and Applied Biosciences ETH Zurich USI-Campus Via Giuseppe Buffi 13 LuganoC-6900 Switzerland Atomistic Simulation Centre School of Mathematics and Physics Queen’s University Belfast BelfastBT7 1NN United Kingdom Laboratory of Computational Science and Modelling EPFL Switzerland

This work examines the conformational ensemble involved in β-hairpin folding by means of advanced molecular dynamics simulations and dimensionality reduction. A fully atomistic description of the protein and the surrounding solvent molecules is used and this complex energy landscape is sampled by means of parallel tempering metadynamics simulations. The ensemble of configurations explored is analysed using the recently proposed sketch-map algorithm. Further simulations allow us to probe how mutations affect the structures adopted by this protein. We find that many of the configurations adopted by a mutant are the same as those adopted by the wild type protein. Furthermore, certain mutations destabilize secondary structure containing configurations by preventing the formation of hydrogen bonds or by promoting the formation of new intramolecular contacts. Our analysis demonstrates that machine-learning techniques can be used to study the energy landscapes of complex molecules and that the visualizations that are generated in this way provide a natural basis for examining how the stabilities of particular configurations of the molecule are affected by factors such as temperature or structural mutations. Copyright © 2023, The Authors. All rights reserved.

关键词： Proteins

Revelation of pivotal genes pertinent to Alzheimer’s pathogenesis: A methodical evaluation of 32 GEO datasets

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Research Square

Research Square 2021年

作者： Sree, Hema G.N.S. Rajalekshmi, Saraswathy Ganesan Burri, Raghunadha R. Pharmacological Modelling and Simulation Centre Faculty of Pharmacy M. S. Ramaiah University of Applied Sciences Bangalore India Deparment of Pharmacy Practice Faculty of Pharmacy Head Pharmacological Modelling and Simulation Centre M. S. Ramaiah University of Applied Sciences Bangalore India IT BPE Dr. Reddy's Laboratories Limited Telangana Hyderabad500034 India

Background: Alzheimer’s Disease (AD), a dreadful neurodegenerative disorder that affects cognitive and behavioral functions in geriatric population, is characterized by the presence of amyloid deposits and neurofibrillary tangles in hippocampus and cortex regions of the BRAIN. The 2018 World Alzheimer’s Report exemplified a global prevalence of 50 million AD cases and forecasted a threefold rise upto 2 trillion by 2050. Although, there exist numerous genetic association studies pertinent to ad in different ethnicities, yet, critical genetic factors and signaling pathways underlying its pathogenesis still remain ambiguous. This study was aimed to collate and analyze the genetic data retrieved from 32 Gene Expression Omnibus (GEO) datasets belonging to diverse ethnic cohorts in order to identify overlapping Differentially Expressed Genes (DEGs). Stringent selection criteria were framed to shortlist appropriate datasets based on FDR p-value, log FC and relevant details on expression of both upregulated and downregulated DEGs from the same dataset. Results: Among the 32 datasets, only 6 datasets satisfied the selection criteria. Geo2R tool was SUBSEQUENTLY employed to retrieve significant DEGs. Nine common DEGs viz. SLC5A3, BDNF, SST, SERPINA3, RTN3, RGS4, NPTX, ENC1 and CRYM WERE found in more than 60% of the selected datasets. These DEGs were later subjected to Protein-Protein Interaction analysis with 18 Literature Derived Genes specific to AD. Conclusion: Among the nine common DEGs, BDNF, SST, SERPINA3 (AACT), RTN3 and RGS4 exhibited significant interactions with crucial proteins like BACE1, GRIN2B, APP, APOE, COMT, PSEN1, INS, NEP and MAPT. Functional enrichment analysis revealed involvement of these genes in trans-synaptic signalling, chemical transmission, PI3K pathway, receptor ligand activity, G-protein signalling etc. these processes are interlinked with AD pathways. © 2021, CC BY.

关键词： Gene expression

Design and Fabrication Challenges of Integrated Optical Circuits for Quantum Computing Applications

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Design and Fabrication Challenges of Integrated Optical Circ...

International Conference on Transparent Optical Networks

作者： Simeon I. Tsintzos Konstantinos Tsimvrakidis Alexandra Sinani Adonis Bogris James C. Gates Peter G.R. Smith Ali W. Elshaari Val Zwiller Christos Riziotis National Hellenic Research Foundation Theoretical & Physical Chemistry Institute Athens Greece Department of Informatics and Computer Engineering University of West Attica Egaleo Greece Optoelectronics Research Centre University of Southampton Southampton United Kingdom Department of Applied Physics Royal Institute of Technology (KTH) Stockholm Sweden Institute for Advanced Modelling and Simulation University of Nicosia Nicosia Cyprus

The paper presents current design issues, limitations, and fabrication challenges towards the development of hybrid integrated optical circuits with embedded single photon sources, which are critical components for future quantum computing, sensing, and communication systems. Optical nanowires with embedded quantum dots (NWQD) are very promising single photon sources, with several reported results of integration in high index platforms like silicon or silicon nitride. Silica on silicon is a favorable platform for optical computing, providing the high degree of customization when combined with direct laser writing techniques for definition of optical structures with refractive index modification. However, the low ~10 -3 achievable refractive index contrast imposes strict limitations on the compatibility with NWQD resulting in general in low coupling efficiency as shown in this work. Consideration of several design and fabrication issues demonstrates the potential for NQWD integration in laser written silica based optical circuits with adequate efficiency for practical applications.

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Tree-Cotree-Based Tearing and Interconnecting for 3D Magnetostatics: A Dual-Primal Approach

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arXiv 2024年

作者： Mally, Mario Kapidani, Bernard Merkel, Melina Schöps, Sebastian Vázquez, Rafael Computational Electromagnetics Group Technische Universität Darmstadt Darmstadt64289 Germany Centre for Computational Engineering Technische Universität Darmstadt Darmstadt64289 Germany Chair of Numerical Modelling and Simulation École Polytechnique Fédérale de Lausanne Lausanne1015 Switzerland Department of Applied Mathematics Universidade de Santiago de Compostela Santiago de Compostela15782 Spain Santiago de Compostela15782 Spain

The simulation of electromagnetic devices with complex geometries and large-scale discrete systems benefits from advanced computational methods like IsoGeometric Analysis and Domain Decomposition. In this paper, we employ both concepts in an Isogeometric Tearing and Interconnecting method to enable the use of parallel computations for magnetostatic problems. We address the underlying non-uniqueness by using a graph-theoretic approach, the tree-cotree decomposition. The classical tree-cotree gauging is adapted to be feasible for parallelization, which requires that all local subsystems are uniquely solvable. Our contribution consists of an explicit algorithm for constructing compatible trees and combining it with a dual-primal approach to enable parallelization. The correctness of the proposed approach is proved and verified by numerical experiments, showing its accuracy, scalability and optimal convergence. Copyright © 2024, The Authors. All rights reserved.

关键词： Magnetostatics

Evaluation of TRMM 3B43 V7 precipitation data in varied Moroccan climatic and topographic zones

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Mediterranean Geoscience Reviews 2024年第2期6卷 159-175页

作者： Aqnouy, Mourad Ommane, Younes Ouallali, Abdessalam Gourfi, Abdelali Ayele, Gebiaw T. El Yousfi, Yassine Bouizrou, Ismail Stitou El Messari, Jamal Eddine Zettam, Amin Melesse, Assefa M. Ndehedehe, Christopher E. Abioui, Mohamed Briak, Hamza Applied Geology Research Laboratory AGRSRT Department of Geosciences Faculty of Sciences and Techniques Moulay Ismail University of Meknes Errachidia Morocco Modelling Simulation and Data Analysis Mohammed VI Polytechnic University (UM6P) Ben Guerir Morocco GPE Laboratory Faculty of Sciences and Techniques Hassan II University of Mohammedia Mohammedia Morocco ESO UMR 6590 UNIV Angers CNRS SFR Confluences UFR LLSH Angers France Australian Rivers Institute and School of Engineering and Built Environment Griffith University Nathan Australia Research Team: Water and Environment Management Laboratory of Applied Sciences (LSA) National School of Applied Sciences Al Hoceima Abdelmalek Essaadi University Tétouan Morocco Functional Ecology and Environmental Engineering Laboratory Faculty of Sciences and Techniques Sidi Mohamed Ben Abdellah University Fez Morocco Department of Agriculture Food Environment and Forestry (DAGRI) University of Florence Florence Italy Department of Geology Faculty of Sciences Abdelmalek Essaadi University Tétouan Morocco LECGEN SNVSTU Abou Bekr Belkaid University (UABB) Tlemcen Algeria Department of Earth and Environment Florida International University Miami FL United States School of Environment and Science Griffith University Nathan QLD Australia Geosciences Environment and Geomatics Laboratory (GEG) Department of Earth Sciences Faculty of Sciences Ibnou Zohr University Agadir Morocco MARE-Marine and Environmental Sciences Centre-Sedimentary Geology Group Department of Earth Sciences Faculty of Sciences and Technology University of Coimbra Coimbra Portugal Laboratory for Sustainable Innovation and Applied Research Universiapolis—International University of Agadir Agadir Morocco Center of Excellence for Soil and Fertilizer Research in Africa (CESFRA) AgroBioSciences (AgBS) Mohammed VI Polytechnic University (UM6P) Ben Guerir Morocco

Hydrologists in developing countries face a major challenge due to the lack of ground data. This study evaluates the performance of the monthly Tropical Rainfall Measurement Mission (TRMM) algorithm 3B43 V7 using 172 ground rainfall measurement stations (GRMS) over Morocco (1998–2018). The performance of the TRMM 3B43 V7 was assessed using four well-known metrics (KGE, R², PBIAS, and RSR). The evaluation was undertaken based on (1) a point-to-pixel scale, (2) sub-regions of Morocco, (3) climatic zones, and (4) different ranges of altitudes. Results indicate that the TRMM 3B43 V7 provides satisfactory attribution in most regions of Morocco, with an average R² higher than 0.54, except in the south areas, which have the lowest R² between 0.29 and 0.41. The best R² of 0.95 was observed in the Tangier-Tetouan-Al Hoceima region. The other performance criteria (KGE: 0.93, RSR: 0.21, PBIAS: − 5.5) indicate that TRMM 3B43 V7 is consistent with in situ data but slightly underestimated. At the point-to-pixel scale, KGE and R² show that 61% and 52% of stations present satisfactory to good results, respectively. The PBIAS shows a large overestimation over most parts of Morocco, particularly the southern part. TRMM 3B43V7 performs better in the Mediterranean climate than in other climatic zones. TRMM 3B43 V7 harmonises GRMS slightly in low elevation zones, while average PBIAS show a global overestimation, increasing in high and low elevations. The results of this study confirm that TRMM 3B43 V7 provides a vital baseline tool to assist Moroccan Hydraulic Basin agencies. Graphical abstract: (Figure presented.) © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2024.

关键词： GRMS Morocco Rainfall Topography TRMM 3B43 V7

A U-Net-Based Self-Stitching Method for Generating Periodic Grain Structures

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arXiv 2023年

作者： Ji, Ye Koeppe, Arnd Altschuh, Patrick Griem, Lars Rajagopal, Deepalaxmi Nestler, Britta Chen, Weijin Zhang, Yi Zheng, Yue Centre for Physical mechanics and Biophysics School of Physics Sun Yat-Sen University Xin’gang West Road 135 Guangdong Guangzhou510275 China Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices School of Physics Xin’gang West Road 135 Guangdong Guangzhou510275 China State Key Laboratory of Optoelectronic Materials and Technologies School of Physics Xin’gang West Road 135 Guangdong Guangzhou510275 China Institute for Applied Materials–Microstructure Modelling and Simulation Karlsruhe Institute of Technology Strasse am Forum 7 Baden-Württemberg Karlsruhe76131 Germany Institute for Digital Materials Science Karlsruhe University of Applied Sciences Moltkestr. 30 Baden-Württemberg Karlsruhe76133 Germany

When modeling microstructures, the computational resource requirements increase rapidly as the simulation domain becomes larger. As a result, simulating a small representative fraction under periodic boundary conditions is often a necessary simplification. However, the truncated structures leave nonphysical boundaries, which are detrimental to numerical modeling. Here, we propose a self-stitching algorithm for generating periodic structures, demonstrated in a grain structure. The main idea of our algorithm is to artificially add structural information between mismatched boundary pairs, using the hierarchical spatial predictions of the U-Net. The algorithm provides an automatic and unbiased way to obtain periodic boundaries in grain structures and can be applied to porous microstructures in a similar way. Copyright © 2023, The Authors. All rights reserved.

关键词： Periodic structures