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Introduction to Quantum Transport
Papers | 30 Jan 2022 | Contributor(s):: Supriyo Datta
Everyone is familiar with the amazing performance of a modern smartphone, powered by a billion-plus nanotransistors, each having an active region that is barely a few hundred atoms long. The same amazing technology has also led to a deeper understanding of the nature of current flow and heat...
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Bandgap Manipulation of Armchair Graphene nanoribbon
Papers | 01 Sep 2020 | Contributor(s):: Lance Fernandes
Bandgap Manipulation is very important for various applications. Optical Devices need smaller Bandgap where as Diode's need larger Bandgap. Armchair graphene Nanoribbon (AGNR) has a special property where if the numbers of atoms are multiple of three or multiple of three plus one, they are...
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Transition to Atomic Wire Electrode Actuates Gold-thiol Spin Valve
Papers | 04 Aug 2020 | Contributor(s):: Avinash Prakash
In resemblance of the mechanically-controlled break junction, we considered the molecule 1,4-benzenedithiol (1,4-BDT) making ohmic contacts with gold in three distinct configurations of the gold electrodes. Simulations of non-equilibrium charge transport within density functional theory,...
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Modular Approach to Spintronics
Papers | 28 Apr 2015 | Contributor(s):: Kerem Yunus Camsari
There has been enormous progress in the last two decades, effectively combining spintronics and magnetics into a powerful force that is shaping the field of memory devices. New materials and phenomena continue to be discovered at an impressive rate, providing an ever-increasing set of building...
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Efficiency Enhancement for Nanoelectronic Transport Simulations
Papers | 02 Feb 2014 | Contributor(s):: Jun Huang
PhD thesis of Jun HuangContinual technology innovations make it possible to fabricate electronic devices on the order of 10nm. In this nanoscale regime, quantum physics becomes critically important, like energy quantization effects of the narrow channel and the leakage currents due to tunneling....
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Physics and Simulation of Nanoscale Electronic and Thermoelectric Devices
Papers | 28 Jun 2013 | Contributor(s):: raseong kim
For the past few decades, transistors have been continuously scaled. Dimensions are now at the nanoscale, and device performance has dramatically improved. Nanotechnology is also achieving breakthroughs in thermoelectrics, which have suffered from low efficiencies for decades. As the device scale...
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Device Physics Studies of III-V and Silicon MOSFETS for Digital Logic
Papers | 28 Jun 2013 | Contributor(s):: Himadri Pal
III-V's are currently gaining a lot of attraction as possible MOSFET channel materials due to their high intrinsic mobility. Several challenges, however, need to be overcome before III-V's can replace silicon (Si) in extremely scaled devices. The effect of low density-of-states of III-V materials...
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Quantum and Atomistic Effects in Nanoelectronic Transport Devices
Papers | 28 Jun 2013 | Contributor(s):: Neophytos Neophytou
As devices scale towards atomistic sizes, researches in silicon electronic device technology are investigating alternative structures and materials. As predicted by the International Roadmap for Semiconductors, (ITRS), structures will evolve from planar devices into devices that include 3D...
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Exploring New Channel Materials for Nanoscale CMOS
Papers | 28 Jun 2013 | Contributor(s):: Anisur Rahman
The improved transport properties of new channel materials, such as Ge and III-V semiconductors, along with new device designs, such as dual gate, tri gate or FinFETs, are expected to enhance the performance of nanoscale CMOS devices. Novel process techniques, such as ALD, high-# dielectrics, and...
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Carbon Nanotube Electronics: Modeling, Physics, and Applications
Papers | 28 Jun 2013 | Contributor(s):: Jing Guo
In recent years, significant progress in understanding the physics of carbon nanotube electronic devices and in identifying potential applications has occurred. In a nanotube, low bias transport can be nearly ballistic across distances of several hundred nanometers. Deposition of high-k gate...
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Physics and Simulation of Quasi-Ballistic Transport in Nanoscale Transistors
Papers | 28 Jun 2013 | Contributor(s):: Jung-Hoon Rhew
The formidable progress in microelectronics in the last decade has pushed thechannel length of MOSFETs into decanano scale and the speed of BJTs into hundreds of gigahertz. This progress imposes new challenges on device simulation as the essential physics of carrier transport departs that of...
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Dissipative Quantum Transport in Semiconductor Nanostructures
Papers | 28 Dec 2011 | Contributor(s):: Peter Greck
In this work, we investigate dissipative quantum transport properties of an open system. After presenting the background of ballistic quantum transport calculations, a simple scattering mechanism, called Büttiker Probes, is introduced. Then, we assess the properties of the Büttiker Probe model...
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Surface scattering: Made simple
Papers | 03 Sep 2010 | Contributor(s):: Dmitri Nikonov, Himadri Pal
Surface scattering in a quantum well.
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Quantum transport in semiconductor nanostructures
Papers | 04 Mar 2010 | Contributor(s):: Tillmann Christoph Kubis
PhD thesis of Tillmann Christoph KubisThe main objective of this thesis is to theoretically predict the stationary charge and spin transport in mesoscopic semiconductor quantum devices in the presence of phonons and device imperfections. It is well known that the nonequilibrium Green's function...
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Scattering in NEGF: Made simple
Papers | 09 Nov 2009 | Contributor(s):: Dmitri Nikonov, Himadri Pal, George Bourianoff
Formalism for describing electron-phonon scattering, surface scattering, and spin relaxation is dervied for the Keldysh non-equilibrium Green's functions (NEGF) method. Approximation useful for efficient numerical solution are described. The specific case of the nanoMOS simulator is...
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Application of the Keldysh Formalism to Quantum Device Modeling and Analysis
Papers | 14 Jan 2008 | Contributor(s):: Roger Lake
The effect of inelastic scattering on quantum electron transport through layered semi-conductor structures is studied numerically using the approach based on the non-equilibrium Green's function formalism of Keldysh, Kadanoff, and Baym. The Markov assumption is not made, and the energy coordinate...
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Electron-Phonon and Electron-Electron Interactions in Quantum Transport
Papers | 14 Jan 2008 | Contributor(s):: Gerhard Klimeck
The objective of this work is to shed light on electron transport through sub-micron semi-conductor structures, where electronic state quantization, electron-electron interactions and electron-phonon interactions are important. We concentrate here on the most developed vertical quantum device,...
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Multidimensional nanoscale device modeling: the finite element method applied to the non-equilibrium Green's function formalism
Papers | 31 Oct 2006 | Contributor(s):: POLIZZI ERIC, Supriyo Datta
This work deals with the modeling and the numerical simulation of quantum transport in multidimensional open nanoscale devices. The electron transport in the device is described using the Non-Equilibrium Green's Functions (NEGF) formalism and the variational form of the problem is solved using...
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Non Equilibrium Green's Functions for Dummies: Introduction to the One Particle NEGF equations
Papers | 30 Oct 2006 | Contributor(s):: Magnus Paulsson
Non equilibrium Green's function methods are regularly used to calculate current and charge densities in nanoscale (both molecular and semiconductor) conductors under bias. This method is mainly used for ballistic conduction but may be extended to include inelastic scattering. In this tutorial...
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Modeling Quantum Transport in Nanoscale Transistors
Papers | 30 Oct 2006 | Contributor(s):: ramesh venugopal
As critical transistor dimensions scale below the 100 nm (nanoscale) regime, quan- tum mechanical effects begin to manifest themselves and affect important device performance metrics. Therefore, simulation tools which can be applied to design nanoscale transistors in the future, require new...