The non-equilibrium Greens function (NEGF) formalism provides a powerful conceptual and computational framework for treating quantum transport in nanodevices. It goes beyond the Landauer approach for ballistic, non-interacting electronics to include inelastic scattering and strong correlation effects at an atomistic level.
Check out Supriyo Datta's NEGF page for more information, or browse through the various resources listed below.
ABACUS Bandstructure Models (Spring 2022)
05 May 2022 | | Contributor(s):: Gerhard Klimeck
In the third session, Dr. Klimeck will give a brief overview of ABACUS and demonstrate several bandstructure tools. With these, students can explore the Standard Periodic Potential aka Kronig-Penney model as well as bandstructure formation by transmission through finite barriers....
Introduction to Quantum Transport
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...
ABACUS Bandstructure Models (Winter 2021)
21 Dec 2021 | | Contributor(s):: Gerhard Klimeck
In the third session, Dr. Klimeck will give a brief overview of ABACUS and demonstrate several bandstructure tools. With these, students can explore the Standard Periodic Potential aka Kronig-Penney model as well as bandstructure formation by transmission through finite barriers...
IWCN 2021: How to Preserve the Kramers-Kronig Relation in Inelastic Atomistic Quantum Transport Calculations
15 Jul 2021 | | Contributor(s):: Daniel Alberto Lemus, James Charles, Tillmann Christoph Kubis
The nonequilibrium Green’s function method (NEGF) is often used to predict quantum transport in atomically resolved nanodevices. This yields a high numerical load when inelastic scattering is included. Atomistic NEGF had been regularly applied on nanodevices, such as nanotransistors....
IWCN 2021: Interfacial Trap Effects in InAs Gate-all-around Nanowire Tunnel Field- Effect Transistors: First-Principles-Based Approach
15 Jul 2021 | | Contributor(s):: Hyeongu Lee, SeongHyeok Jeon, Cho Yucheol, Mincheol Shin
In this work, we investigated the effects of the traps, Arsenic dangling bond (AsDB) and Arsenic anti-site (AsIn) traps, in InAs gate-all-around nanowire TFETs, using the trap Hamiltonian obtained from the first-principles calculations. The transport properties were treated by nonequilibrium...
IWCN 2021: Ab initio Quantum Transport Simulation of Lateral Heterostructures Based on 2D Materials: Assessment of the Coupling Hamiltonians
14 Jul 2021 | | Contributor(s):: Adel Mfoukh, Marco Pala
Lateral heterostructures based on lattice-matched 2D materials are a promising option to design efficient electron devices such as MOSFETs , tunnel-FETs  and energy-filtering FETs . In order to rigorously describe the transport through such heterostructures, an ab-initio approach based...
IWCN 2021: Thermoelectric Properties of Complex Band and Nanostructured Materials
14 Jul 2021 | | Contributor(s):: Neophytos Neophytou, Patrizio Graziosi, Vassilios Vargiamidis
In this work, we describe a computational framework to compute the electronic and thermoelectric transport in materials with multi-band electronic structures of an arbitrary shape by coupling density function theory (DFT) bandstructures to the Boltzmann Transport Equation (BTE).
Recursive algorithm for NEGF in Python GPU version
02 Feb 2021 | | Contributor(s):: Ning Yang, Tong Wu, Jing Guo
This folder contains two Python functions for GPU-accelerated simulation, which implements the recursive algorithm in the non-equilibrium Green’s function (NEGF) formalism. Compared to the matlab implementation , the GPU version allows massive parallel running over many cores on GPU...
Compact NEGF-Based Solver for Double-Gate MOSFETs
17 Nov 2020 | | Contributor(s):: Fabian Hosenfeld, Alexander Kloes
Fast simulation of the DC current in a nanoscale double-gate MOSFET including thermionic emission and source-to-drain tunneling current.
Atomistic Green’s Functions: The Beauty of Self-energies
28 Oct 2020 | | Contributor(s):: Tillmann Christoph Kubis
This presentation gives an introduction to NEGF. It will be explained how self-energies cause NEGF to fundamentally differ from most other quantum methods. Atomistic examples of phonon and impurity scattering self-energies agree quantitatively with experiments.
Bandgap Manipulation of Armchair Graphene nanoribbon
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...
Transition to Atomic Wire Electrode Actuates Gold-thiol Spin Valve
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,...
Bandstructure Effects in Nano Devices With NEMO: from Basic Physics to Real Devices and to Global Impact on nanoHUB.org
08 Mar 2019 | | Contributor(s):: Gerhard Klimeck
This presentation will intuitively describe how bandstructure is modified at the nanometer scale and what some of the consequences are on the device performance.
Niger Sultana Mimi
Non-linear Poisson eq. convergence issue for self-consistent calculation in NEGF
Closed | Responses: 0
I was working on Prof. S. Datta's code (https://nanohub.org/resources/19564) for 1D diode. I find the convergence rate is highly sensitive to the initial guess, although...
NEMO5, a Parallel, Multiscale, Multiphysics Nanoelectronics Modeling Tool: From Basic Physics to Real Devices and to Global Impact on nanoHUB.org
10 Nov 2016 | | Contributor(s):: Gerhard Klimeck
The Nanoelectronic Modeling tool suite NEMO5 is aimed to comprehend the critical multi-scale, multi-physics phenomena and deliver results to engineers, scientists, and students through efficient computational approaches. NEMO5’s general software framework easily includes any kind of...
NEMO5, a Parallel, Multiscale, Multiphysics Nanoelectronics Modeling Tool
19 Sep 2016 | | Contributor(s):: Gerhard Klimeck
Atomistic Modeling of Nano Devices: From Qubits to Transistors
13 Apr 2016 | | Contributor(s):: Rajib Rahman
In this talk, I will describe such a framework that can capture complex interactions ranging from exchange and spin-orbit-valley coupling in spin qubits to non-equilibrium charge transport in tunneling transistors. I will show how atomistic full configuration interaction calculations of exchange...