
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 multiscale, multiphysics 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
The Nanoelectronic Modeling tool suite NEMO5 is aimed to comprehend the critical multiscale, multiphysics phenomena and deliver results to engineers, scientists, and students through efficient computational approaches. NEMO5’s general software framework easily includes any kind of...

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 spinorbitvalley coupling in spin qubits to nonequilibrium charge transport in tunneling transistors. I will show how atomistic full configuration interaction calculations of exchange...

Selfenergies: Opening Doors for Nanotechnology
07 Apr 2016   Contributor(s):: Tillmann Christoph Kubis
In this talk, it will be shown how the concept of selfenergies can be used to interface all these fields into the same nanotechnology modeling framework. Selfenergies are most commonly used in the quantum transport method of nonequilibrium Green’s functions (NEGF). The NEGF method is...

Phonon Interactions in SingleDopantBased Transistors: Temperature and Size Dependence
25 Nov 2015   Contributor(s):: Marc Bescond, Nicolas Cavassilas, Salim Berrada
IWCE 2015 presentation. in this work we investigate the dependence of electronphonon scattering in single dopantbased nanowire transistor with respect to temperature and dimensions. we use a 3d realspace nonequilibrium green': ; s function (negf) approach where electronphonon...

Mode Space Tight Binding Model for UltraFast Simulations of IIIV Nanowire MOSFETs and Heterojunction TFETs
13 Nov 2015   Contributor(s):: Aryan Afzalian, Jun Huang, Hesameddin Ilatikhameneh, Santiago Alonso Perez Rubiano, Tillmann Christoph Kubis, Michael Povolotskyi, Gerhard Klimeck
IWCE 2015 presentation. we explore here the suitability of a mode space tight binding algorithm to various iiiv homo and heterojunction nanowire devices. we show that in iiiv materials, the number of unphysical modes to eliminate is very high compared to the si case previously reported...

Density Functional Tight Binding (DFTB) Modeling in the Context of UltraThin SilicononInsulator MOSFETs
10 Oct 2015   Contributor(s):: Stanislav Markov
IWCE 2015 presentation. We investigate the applicability of density functional tight binding (DFTB) theory [1][2], coupled to nonequilibrium Green functions (NEGF), for atomistic simulations of ultrascaled electron devices, using the DFTB+ code [3][4]. In the context of ultrathin...

NonEquilibrium Green's Function (NEGF): A Different Perspective
18 Sep 2015   Contributor(s):: Supriyo Datta
The NEGF method was established in the 1960’s through the classic work of Keldysh and others [1] using the methods of many body perturbation theory (MBPT) and this approach is widely used in the literature [2]. By contrast I have introduced a different approach starting with the...

Tutorial 4a: High Bias Quantum Transport in Resonant Tunneling Diodes
29 Mar 2011   Contributor(s):: Gerhard Klimeck
Outline:Resonant Tunneling Diodes  NEMO1D: Motivation / History / Key InsightsOpen 1D Systems: Transmission through Double Barrier Structures  Resonant TunnelingIntroduction to RTDs: Linear Potential DropIntroduction to RTDs: Realistic Doping ProfilesIntroduction to RTDs: Relaxation Scattering...

Lecture 3: Introduction to NEGF
08 Sep 2010   Contributor(s):: Supriyo Datta

Nonequilibrium Green’s functions theory: Transport and optical gain in THz quantum cascade lasers
26 Mar 2010   Contributor(s):: Tillmann Christoph Kubis
Quantum cascade lasers (QCLs) are promising sources of coherent THz radiation. However, state of the art THzQCLs are still limited to cryogenic temperatures. The charge transport in these QCLs is subject to coherent quantum phenomena, such as quantum tunneling, confinement and interferences as...

Nanoelectronic Modeling nanoHUB Demo 2: RTD simulation with NEGF
09 Mar 2010   Contributor(s):: Gerhard Klimeck
Demonstration of resonant tunneling diode (RTD) simulation using the RTD Simulation with NEGF Tool with a Hartree potential model showing potential profile, charge densities, currentvoltage characteristics, and resonance energies. Also demonstrated is a RTD simulation using a ThomasFermi...

Nanoelectronic Modeling nanoHUB Demo 1: nanoHUB Tool Usage with RTD Simulation with NEGF
09 Mar 2010   Contributor(s):: Gerhard Klimeck
Demonstration of running tools on the nanoHUB. Demonstrated is the RTD Simulation with NEGF Tool using a simple leveldrop potential model and a more realistic device using a ThomasFermi potential model.

Nanoelectronic Modeling Lecture 26: NEMO1D 
09 Mar 2010   Contributor(s):: Gerhard Klimeck
NEMO1D demonstrated the first industrial strength implementation of NEGF into a simulator that quantitatively simulated resonant tunneling diodes. The development of efficient algorithms that simulate scattering from polar optical phonons, acoustic phonons, alloy disorder, and interface...

ECET 499N Lecture 5a: Nanoelectronics III  Datta Lecture Review
19 Feb 2010   Contributor(s):: Helen McNally

Nanoelectronic Modeling Lecture 22: NEMO1D  Motivation, History and Key Insights
07 Feb 2010   Contributor(s):: Gerhard Klimeck
The primary objective of the NEMO1D tool was the quantitative modeling of high performance Resonant Tunneling Diodes (RTDs). The software tool was intended for Engineers (concepts, fast turnaround, interactive) and Scientists (detailed device anaysis). Therefore various degrees of...

Nanoelectronic Modeling Lecture 21: Recursive Green Function Algorithm
07 Feb 2010   Contributor(s):: Gerhard Klimeck
The Recursive Green Function (RGF) algorithms is the primary workhorse for the numerical solution of NEGF equations in quasi1D systems. It is particularly efficient in cases where the device is partitioned into reservoirs which may be characterized by a nonHermitian Hamiltonian and a central...

Nanoelectronic Modeling Lecture 20: NEGF in a Quasi1D Formulation
27 Jan 2010   Contributor(s):: Gerhard Klimeck, Samarth Agarwal, Zhengping Jiang
This lecture will introduce a spatial discretization scheme of the Schrödinger equation which represents a 1D heterostructure like a resonant tunneling diode with spatially varying band edges and effective masses.

Nanoelectronic Modeling Lecture 19: Introduction to RTDs  Asymmetric Structures
27 Jan 2010   Contributor(s):: Gerhard Klimeck
This lecture explores this effect in more detail by targeting an RTD that has a deliberate asymmetric structure. The collector barrier is chosen thicker than the emitter barrier. With this setup we expect that the tunneling rate into the RTD from the emitter is faster than the tunneling rate...

Nanoelectronic Modeling Lecture 17: Introduction to RTDs  Relaxation Scattering in the Emitter
27 Jan 2010   Contributor(s):: Gerhard Klimeck
Realistic RTDs will have nonlinear electrostatic potential in their emitter. Typically a triangular well is formed in the emitter due to the applied bias and the emitter thus contains discrete quasi bound states.