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Related papers: The Generalized Kadanoff-Baym Ansatz with Initial …

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The quantum dynamics of fermionic or bosonic many-body systems following external excitation can be successfully studied using two-time nonequilibrium Green's functions (NEGF) or single-time reduced density matrix methods. Approximations…

Strongly Correlated Electrons · Physics 2022-07-12 Erik Schroedter , Jan-Philip Joost , Michael Bonitz

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

This article presents an overview on recent progress in the theory of nonequilibrium Green functions (NEGF). NEGF, presently, are the only \textit{ab-initio} quantum approach that is able to study the dynamics of correlations for long times…

Strongly Correlated Electrons · Physics 2019-12-20 N. Schluenzen , S. Hermanns , M. Scharnke , M. Bonitz

We introduce a versatile method to compute electronic steady state properties of strongly correlated extended quantum systems out of equilibrium. The approach is based on dynamical mean-field theory (DMFT), in which the original system is…

Strongly Correlated Electrons · Physics 2013-03-05 Enrico Arrigoni , Michael Knap , Wolfgang von der Linden

Using non-equilibrium Green's functions (NEGF), we calculate the current through an interacting region connected to non-interacting leads. The problem is reformulated in such a way that a Landauer-like term appears in the current as well as…

Mesoscale and Nanoscale Physics · Physics 2015-05-19 H. Ness , L. K. Dash , R. W. Godby

We put forward a practical nonequilibrium Green's function (NEGF) scheme to perform real-time evolutions of many-body interacting systems driven out of equilibrium by external fields. CHEERS is a computational tool to solve the NEGF…

Other Condensed Matter · Physics 2018-10-09 E. Perfetto , G. Stefanucci

The nonequilibrium Dyson (or Kadanoff-Baym) equation, which is an equation of motion with long-range memory kernel for real-time Green functions, underlies many numerical approaches based on the Keldysh formalism. In this paper we map the…

Strongly Correlated Electrons · Physics 2014-02-05 Karsten Balzer , Martin Eckstein

The interaction with time-dependent external fields, especially the interplay between time-dependent driving and quantum correlations, changes the familiar picture of electron transport through nanoscale systems. Although the exact solution…

Mesoscale and Nanoscale Physics · Physics 2020-02-13 Thomas D. Honeychurch , Daniel S. Kosov

We establish the foundations of a nonequilibrium theory of quantum thermodynamics for noninteracting open quantum systems strongly coupled to their reservoirs within the framework of the nonequilibrium Green functions (NEGF). The energy of…

Statistical Mechanics · Physics 2015-03-18 Massimiliano Esposito , Maicol A. Ochoa , Michael Galperin

We present a non-perturbative Floquet-based non-equilibrium Green's function (NEGF) method to study electron transport in a quantum system driven simultaneously by multiple independent terms (multi-mode). We first derive the two-mode…

Other Condensed Matter · Physics 2026-05-20 Vahid Mosallanejad , Wenjie Dou

This review deals with the nonequilibrium Green's function (NEGF) method applied to the problems of energy transport due to atomic vibrations (phonons), primarily for small junction systems. We present a pedagogical introduction to the…

Mesoscale and Nanoscale Physics · Physics 2013-05-28 Jian-Sheng Wang , Bijay Kumar Agarwalla , Huanan Li , Juzar Thingna

A recently developed method for incorporating initial binary correlations into the Kadanoff-Baym equations (KBE) is used to derive a generalized T-matrix approximation for the self-energies. It is shown that the T-matrix obtains additional…

Statistical Mechanics · Physics 2015-06-25 D. Semkat , D. Kremp , M. Bonitz

The theoretical description of materials' properties driven out of equilibrium has important consequences in various fields such as semiconductor spintronics, nonlinear optics, continuous and discrete quantum information science and…

Materials Science · Physics 2025-09-18 Jacopo Simoni , Gabriele Riva , Yuan Ping

Computational difficulties aside, nonequilibrium Green's functions appear ideally suited for investigating the dynamics of central nuclear reactions. Many particles actively participate in those reactions. At the two energy extremes for the…

Nuclear Theory · Physics 2018-05-17 Hossein Mahzoon , Pawel Danielewicz , Arnau Rios

The quantum dynamics of correlated fermionic or bosonic many-body systems following external excitation can be successfully studied using nonequilibrium Green functions (NEGF) or reduced density matrix methods. Approximations are introduced…

Strongly Correlated Electrons · Physics 2023-12-27 Erik Schroedter , Björn Jakob Wurst , Jan-Philip Joost , Michael Bonitz

This article reviews the application of the non-equilibrium Green's function formalism to the simulation of novel photovoltaic devices utilizing quantum confinement effects in low dimensional absorber structures. It covers well-known…

Mesoscale and Nanoscale Physics · Physics 2012-06-14 U. Aeberhard

We present a full ab-inito description of the coupled out-of-equilibrium dynamics of photons, phonons, and electrons. In the present approach the quantised nature of the electromagnetic field as well as of the nuclear oscillations is fully…

Mesoscale and Nanoscale Physics · Physics 2015-12-24 Pedro Melo , Andrea Marini

Linear density response functions are calculated for symmetric nuclear matter of normal density by time-evolving two-time Green's functions in real time. Of particular interest is the effect of correlations. The system is therefore…

Nuclear Theory · Physics 2016-05-04 H. S. Köhler , N. H. Kwong

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

Fast and reliable manipulation with qubits is fundamental for any quantum technology. The implementation of these manipulations in physical systems is the focus of studies involving optimal control theory. Realistic physical devices are…

Quantum Physics · Physics 2025-03-28 Haoran Sun , Michael Galperin