English
Related papers

Related papers: An Approximate Framework for Quantum Transport Cal…

200 papers

We consider a projection operator approach to the non-equilbrium Green function equation-of-motion (PO-NEGF EOM) method. The technique resolves problems of arbitrariness in truncation of an infinite chain of EOMs, and prevents violation of…

Mesoscale and Nanoscale Physics · Physics 2014-10-28 Maicol A. Ochoa , Michael Galperin , Mark A. Ratner

The nonequilibrium description of quantum systems requires, for more than two or three particles, the use of a reduced description to be numerically tractable. Two possible approaches are based on either reduced density matrices or…

Strongly Correlated Electrons · Physics 2013-09-19 S. Hermanns , K. Balzer , M. Bonitz

Nonequilibrium Greens function techniques (NEGF) combined with density functional theory (DFT) calculations have become a standard tool for the description of electron transport through single molecule nanojunctions in the coherent…

Mesoscale and Nanoscale Physics · Physics 2015-11-05 Victor Geskin , Robert Stadler , Jérôme Cornil

This research demonstrates analytical time-dependent non-equilibrium green function (TD-NEGF) algorithms to investigate dynamical functionalities of quantum devices, especially for photon-assisted transports. Together with the lumped…

Mesoscale and Nanoscale Physics · Physics 2021-06-08 I-Lin Ho

As the characteristic lengths of advanced electronic devices are approaching the atomic scale, ab initio simulation method, with fully consideration of quantum mechanical effects, becomes essential to study the quantum transport phenomenon…

Mesoscale and Nanoscale Physics · Physics 2019-07-17 Meng Ye , Xiangwei Jiang , Shu-Shen Li , Lin-Wang Wang

We present a detailed comparison of three different methods designed to tackle nonequilibrium quantum transport, namely the functional renormalization group (fRG), the time-dependent density matrix renormalization group (tDMRG), and the…

Mesoscale and Nanoscale Physics · Physics 2015-05-18 J. Eckel , F. Heidrich-Meisner , S. G. Jakobs , M. Thorwart , M. Pletyukhov , R. Egger

We present novel methods implemented within the non-equilibrium Green function code (NEGF) transiesta based on density functional theory (DFT). Our flexible, next-generation DFT-NEGF code handles devices with one or multiple electrodes…

Mesoscale and Nanoscale Physics · Physics 2016-12-30 Nick Papior , Nicolás Lorente , Thomas Frederiksen , Alberto García , Mads Brandbyge

Considering von Neumann expression for reduced density matrix as thermodynamic entropy of a system strongly coupled to baths, we use nonequilibrium Green's function (NEGF) techniques to derive bath and energy resolved expressions for…

Mesoscale and Nanoscale Physics · Physics 2021-02-17 Nikhil Seshadri , Michael Galperin

We use the effective-mass approximation and the density-functional theory with the local-density approximation for modeling two-dimensional nano-structures connected phase-coherently to two infinite leads. Using the non-equilibrium Green's…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Paula Havu , Ville Havu , Martti Puska , Risto Nieminen

The objective of this paper is to describe a simple phenomenological approach for including incoherent dephasing processes in quantum transport models. The presented illustrative numerical results show this model provides the flexibility of…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Roksana Golizadeh-Mojarad , Supriyo Datta

To explore whether the density-functional theory non-equilibrium Green's function formalism (DFT-NEGF) provides a rigorous framework for quantum transport, we carried out time-dependent density functional theory (TDDFT) calculations of the…

Materials Science · Physics 2011-07-01 ChiYung Yam , Xiao Zheng , GuanHua Chen , Yong Wang , Thomas Frauenheim , Thomas A. Niehaus

By viewing the non-equilibrium transport setup as a quantum open system, we propose a reduced-density-matrix based quantum transport formalism. At the level of self-consistent Born approximation, it can precisely account for the correlation…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Ping Cui , Xin-Qi Li , Jiushu Shao , YiJing Yan

Non-equilibrium Green's function (NEGF) and quantum master equation (QME) are two main classes of approaches for electronic transport. We discuss various Floquet variances of these formalisms for transport properties of a quantum dot driven…

Quantum Physics · Physics 2024-04-10 Vahid Mosallanejad , Yu Wang , Wenjie Dou

In this colloquia review we discuss methods for thermal transport calculations for nanojunctions connected to two semi-infinite leads served as heat-baths. Our emphases are on fundamental quantum theory and atomistic models. We begin with…

Mesoscale and Nanoscale Physics · Physics 2008-05-23 Jian-Sheng Wang , Jian Wang , J. T. Lu

State-of-the-art industrial semiconductor device modeling is based on highly efficient Drift-Diffusion (DD) models that include some quantum corrections for nanodevices. In contrast, latest academic quantum transport models are based on the…

Designing nanoscale electronic devices such as the currently manufactured nanoribbon field-effect transistors (NRFETs) requires advanced modeling tools capturing all relevant quantum mechanical effects. State-of-the-art approaches combine…

A generalized Langevin equation with quantum baths (QMD) for thermal transport is derived with the help of nonequilibrium Green's function (NEGF) formulation. The exact relationship of the quasi-classical approximation to NEGF is…

Mesoscale and Nanoscale Physics · Physics 2009-12-23 Jian-Sheng Wang , Xiaoxi Ni , Jin-Wu Jiang

Since any realistic electronic device has some degree of disorder, predicting disorder effects in quantum transport is a critical problem. Here we report the theory of nonequilibrium coherent potential approximation (NECPA) for analyzing…

Mesoscale and Nanoscale Physics · Physics 2015-06-15 Yu Zhu , Lei Liu , Hong Guo

Two-terminal spintronic devices remain challenging to model under realistic operating conditions, where the interplay of complex electronic structures, correlation effects and bias-driven non-equilibrium dynamics may significantly impact…

Strongly Correlated Electrons · Physics 2025-11-25 Declan Nell , Milos Radonjic , Ivan Rungger , Liviu Chioncel , Stefano Sanvito , Andrea Droghetti

We demonstrate an efficient nonequilibrium Green's function transport calculation procedure based on the real-space finite-difference method. The direct inversion of matrices for obtaining the self-energy terms of electrodes is…

Materials Science · Physics 2024-01-09 Tomoya Ono , Yoshiyuki Egami , Kikuji Hirose