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In the 20th century transistor performance improvement was driven by dimensional scaling; dimensional scaling in turn was driven by scaling of the wavelength of light used for patterning. However, in the last decade, new and innovative techniques have been used to drive transistor performance and dimensional scaling forward. This talk will focus on some of the techniques that have been used to enable Moore’s law over the last decade as well as the prognosis for future scaling.

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Hyun Ku Lee onto favoir

What is MD? Molecular dynamics involves the numerical solution of the classical equations of motion (F=ma) for every single atom in material. The result is a very detailed description of the temporal evolution of the material: we obtain the position, velocity and force of every atom as a function of time. The total force acting on an atom comes from its interaction with other atoms and external fields and an accurate model to describe atomic interactions is critical in any MD simulation. If you are interested in MD read on; you will find more information, additional resources, simulation codes, and online tool that enables running live MD simulations using simply your web-browser. Advantages As compared with other materials simulation techniques, MD exhibits several advantages: The only inputs to the simulation are the interatomic potential used to compute forces on atoms and the initial configuration; all other properties and processes are derived. For example, you cannot dial-in the melting temperature, or the character of the slip planes that will be activated during deformation, how a dislocation might look, nucleate or move, or how phonons interact with each other or with other defects. Consequently, phenomena like size effects in the thermal or mechanical response of materials are naturally captured by MD making a power technique in nanoscience and nanotechnology. Approximations MD is not without approximations and it is important to understand them in order to design meaningful simulations and correctly interpret their results. There are two key approximations: Atomic interactions are now known exactly, and an accurate model to describe them is critical in MD simulations of realistic materials. Atomic forces can be obtained from ab initio electronic structure calculations (such as density functional theory); these methods provide accurate results (not exact) but are computationally intensive. Most MD simulation use of interatomic potentials (or force fields) that describe atomic interactions in terms of functions parameterized to describe specific materials using experimental or ab initio data. These potentials are less accurate and less transferable than ab initio calculations but are computationally less intensive enabling large-scale simulations (up to billions of atoms in current petaFLOP supercomputers). Being based on classical mechanics, MD does not capture quantum effects on ionic dynamics. These effects originate when atomic vibrations around a minimum lead confinement of position and velocity that violates Heisenberg’s uncertainty principle are important when simulations are performed at temperatures below or near the Debye temperature of the material. Learn more about MD at nanoHUB.org An Introduction to Molecular Dynamics. A lecture series by Alejandro Strachan. Video, voiced-over presentations and notes: http://nanohub.org/resources/5838 Overview of Computational Nanoscience: a UC Berkeley Course. By Jeffrey C Grossman, Elif Ertekin. Class notes in pdf format: https://nanohub.org/resources/3944 Short Course on Molecular Dynamics Simulation. By Ashlie Martini. Class notes in pdf format: https://nanohub.org/resources/7570 Online MD simulations at nanoHUB.org

The nanoMATERIALS simulation tool https://nanohub.org/resources/matsimtk enables running live MD simulations in nanoHUB.org. A simple-to-use graphical interface allows users to set up the initial structure, simulation conditions (e.g. thermodynamic ensemble, temperature, strain rate), and output options; advanced options enable users to compute thermal conductivity using non-equilibrium simulations. Learn more about the nanoMATERIALS simulation tool and run simulations via the following tutorials: Running MD on the nanoHUB: The nano-MATERIALS Simulation Toolkit. http://nanohub.org/resources/5843 Materials strength: does size matter? nanoMATERIALS simulation toolkit tutorial. https://nanohub.org/resources/2322 MD in research and education First Principles-based Atomistic and Mesoscale Modeling of Materials. https://nanohub.org/resources/434 Learning Module: Atomic picture of plastic deformation in metals. Teach and learn about the atomic level mechanisms that govern plastic deformation is metals: https://nanohub.org/topics/LearningModulePlasticityMD Other resources

Some of my favorite books and publications on MD Allen, M. P. and D. J. Tildesley. 1989. Computer Simulation of Liquids. Oxford (UK): Oxford University Press. Frenkel, Daan and Berend Smit. 2002. Understanding Molecular Simulation: From Algorithms to Applications. 2nd ed. San Diego: Academic Press..

Downloadable, free of charge, MD codes LAMMPS, the Large-scale Atomic/Molecular Massively Parallel Simulator from Sandia National Labs, is available at: http://lammps.sandia.gov/ . NAMD, from the University of Illinois at Urbana Champain, available at: http://www.ks.uiuc.edu/Research/namd/ GROMACS, GROningen MAchine for Chemical Simulations, is available at: http://www.gromacs.org/

Related codes and resources VMD, molecular visualization, http://www.ks.uiuc.edu/Research/vmd/

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Bogdan Vladislavovich Natalich onto MD

This set of ten presentations accompanied a graduate level course on Molecular Dynamics simulation. The specific objective of the course (and the presentations) is to provide: 1. Awareness of the opportunities and limitations of Molecular Dynamics as a tool for scientific and engineering research 2. Understanding of the compromise between model complexity/realism and computational expense 3. Background that enables interpretation of Molecular Dynamics-based studies reported in the literature

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Profile picture of Bogdan Vladislavovich Natalich

Bogdan Vladislavovich Natalich onto MD

ninithi which is a free and opensource modelling software, can be used to visualize and analyze carbon allotropes used in nanotechnology. You can generate 3-D visualization of Carbon nanotubes, Fullerenes, Graphene and Carbon nanoribbons and analyze the band structures of nanotubes and graphene.

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Yuepei Tsai onto Software

Molecular dynamics simulations are playing an increasingly important role in many areas of science and engineering, from biology and pharmacy to nanoelectronics and structural materials. Recent breakthroughs in methodologies and in first principles-based interatomic potentials significantly increased the range of applicability of MD and the accuracy of its predictions even for new materials not yet fabricated or synthesized. Such predictive power indicates that MD has the potential to play a key role in guiding the design and optimization of new materials with improved properties tailored for specific applications.

The goal of this short course is to provide an introduction to the theory behind MD simulations, describe some of the most exciting recent developments in the field and exemplify its use in various applications. The short course consists of a brief introduction and three lectures.

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Yuepei Tsai onto OpenCourse

This series is a collection of introductory talks describing how you can upload your own content onto nanoHUB.

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Yuepei Tsai onto Nanohub tutorials

One of the most powerful tools on nanoHUB is something we call a workspace, which is a full-featured Linux desktop that you can access any time, any place, from your web browser. Workspaces are fully loaded with the latest nanoHUB software stack, including the Rappture toolkit, Octave, Scilab, a variety of compilers, and other handy utilities. This tutorial shows how to use workspaces for research and for tool development. It shows how to request access to workspaces, how to launch them, how …

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Yuepei Tsai onto Nanohub tutorials

Basic Concepts presents key concepts in nanoelectronics and mesoscopic physics and relates them to the traditional view of electron flow in solids.

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JUNGYUN KWON onto Physics

Instructor: Mark Lundstrom

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JUNGYUN KWON onto Physics

This course was created by Supriyo Datta to convey key concepts of nanoelectronics and quantum transport to students with no background in quantum mechanics or statistical mechanics.

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JUNGYUN KWON onto Physics

This five-week short course aims to introduce students to the thermoelectric theory and applications using a unique, “bottom up” approach to carrier transport that has emerged from research on…

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JUNGYUN KWON onto TE

Basic Concepts presents key concepts in nanoelectronics and mesoscopic physics and relates them to the traditional view of electron flow in solids.

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JUNGYUN KWON onto electronics

A free five-week course on the essential physics of thermal energy at the nanoscale.

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JUNGYUN KWON onto Physics

A five-week course on the basic physics that govern materials at atomic scales.

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JUNGYUN KWON onto Material

This course will introduce the students to the basic concepts and postulates of quantum mechanics. Examples will include simple systems such as particle in an infinite and finite well, 1D and 2D harmonic oscillator and tunneling. Numerous approximation techniques, such as WKB method, time-dependent and time-independent perturbation theory, variational methods and numerical solution methods of the 1D Schrödinger equation, will be presented. The importance of quantum-mechanics in todays life …

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Noe Nieto onto To Read

This course will introduce the students to the basic concepts and postulates of quantum mechanics. Examples will include simple systems such as particle in an infinite and finite well, 1D and 2D harmonic oscillator and tunneling. Numerous approximation techniques, such as WKB method, time-dependent and time-independent perturbation theory, variational methods and numerical solution methods of the 1D Schrödinger equation, will be presented. The importance of quantum-mechanics in todays life …

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Mahesh Anigol onto Quantum Mechanics for Engineers

Nanodevice design through organization of functional biological components; bio-molecular function and bioconjugation techniques in nanotechnology; modulation of biological systems using nanotechnology; issues related to applying biological nanotechnology in food energy, health, and the environment.

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Fabian Marquardt onto Bioinspired Engineering

This five-week short course aims to introduce students to bioelectricity using a unique, “bottom up” approach.

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Fabian Marquardt onto Bioinspired Engineering

The purpose of this independent study is to give students hands-on experience in using computers to model neural systems. A neural system is a system of interconnected neural elements, or units. Students will use existing computer programs which will simulate real neural systems. They will compare the behavior of the model units with neurophysiological data on real neurons. The neural system models will all perform a useful computation, and the similarity between the behaviors of model units …

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Fabian Marquardt onto Bioinspired Engineering

A five week course distilling the principles and physics of electronic nanobiosensors.

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Fabian Marquardt onto Bioinspired Engineering

A five-week course on organic electronic materials, covering molecular properties of organic semiconductors, microstructural characterization of organic semiconductors, and charge generation and…

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Fabian Marquardt onto Bioinspired Engineering

In quantum mechanics the time-independent Schrodinger\‘s equation can be solved for eigenfunctions (also called eigenstates or wave-functions) and corresponding eigenenergies (or energy levels) for a stationary physical system. The wavefunction itself can take on negative and positive values and could be complex. The square magnitude of the wave-function is the probability density of finding the particle in space at that particular energy level.


A quantum dot is a physical system that …

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Deqi Tang onto wavefunctions

VEDA

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Kasinan Suthiwanich onto AFM