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Related papers: Cheers: a linear-scaling KBE+GKBA code

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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 interaction of electrons with quantized phonons and photons underlies the ultrafast dynamics of systems ranging from molecules to solids, and it gives rise to a plethora of physical phenomena experimentally accessible using…

Strongly Correlated Electrons · Physics 2021-07-21 Daniel Karlsson , Robert van Leeuwen , Yaroslav Pavlyukh , Enrico Perfetto , Gianluca Stefanucci

Real-time Green's function simulations of molecular junctions (open quantum systems) are typically performed by solving the Kadanoff-Baym equations (KBE). The KBE, however, impose a serious limitation on the maximum propagation time due to…

Mesoscale and Nanoscale Physics · Physics 2015-06-17 S. Latini , E. Perfetto , A. -M. Uimonen , R. van Leeuwen , G. Stefanucci

The Green's function method has applications in several fields in Physics, from classical differential equations to quantum many-body problems. In the quantum context, Green's functions are correlation functions, from which it is possible…

Mesoscale and Nanoscale Physics · Physics 2016-10-14 Mariana M. Odashima , Beatriz G. Prado , E. Vernek

Quantum many-body methods provide a systematic route to computing electronic properties of molecules and materials, but high computational costs restrict their use in large-scale applications. Due to the complexity in many-electron…

Starting from the {\em ab initio} many-body theory of electrons and phonons, we go through a series of well defined simplifications to derive a set of coupled equations of motion for the electronic occupations and polarizations, nuclear…

Materials Science · Physics 2023-11-08 Gianluca Stefanucci , Enrico Perfetto

Sub-wavelength arrays of quantum emitters offer an efficient free-space approach to coherent light-matter interfacing, using ultracold atoms or two-dimensional solid-state quantum materials. The combination of collectively suppressed…

Quantum Gases · Physics 2024-12-16 Simon Panyella Pedersen , Georg M. Bruun , Thomas Pohl

We generalize the family of approximate momentum average methods to formulate a numerically exact, convergent hierarchy of equations whose solution provides an efficient algorithm to compute the Green's function of a particle dressed by…

Strongly Correlated Electrons · Physics 2021-08-05 Matthew R. Carbone , David R. Reichman , John Sous

In non-equilibrium Green's function calculations the use of the Generalized Kadanoff-Baym Ansatz (GKBA) allows for a simple approximate reconstruction of the two-time Green's function from its time-diagonal value. With this a drastic…

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

Energy functionals of the Green's function can simultaneously provide spectral and thermodynamic properties of interacting electrons' systems. Though powerful in principle, these formulations need to deal with dynamical…

Materials Science · Physics 2024-05-28 Tommaso Chiarotti , Andrea Ferretti , Nicola Marzari

In this paper some new physical notations are given for the Green's functions and equations of motion (EOM) in many body physics with the concept of quasiparticles. It shows how the many body correlations existing in many body systems can…

Strongly Correlated Electrons · Physics 2013-02-20 Qingguo Feng

A new scheme has been proposed to solve the B.E. condenstates in terms of Green's function approach. It has been shown that the radial wave function of two interacting atoms, moving in a common harmonic oscillator potential modified by an…

Quantum Physics · Physics 2007-05-23 Mahendra Sinha Roy

One of the standard generalized-gradient approximations (GGAs) in use in modern electronic-structure theory, PBE, and a recently proposed modification designed specifically for solids, PBEsol, are identified as particular members of a…

Materials Science · Physics 2015-05-13 Luana S. Pedroza , Antonio J. R. da Silva , Klaus Capelle

We show that Green function methods can be straightforwardly applied to nonlinear equations appearing as the leading order of a short time expansion. Higher order corrections can be then computed giving a satisfactory agreement with…

High Energy Physics - Theory · Physics 2008-11-26 Marco Frasca

It is shown that the conventional many-body techniques to calculate the Green's functions can be applied to the wide, compressible edge of a quantum Hall bar. The only ansatz we need is the existence of stable density modes that yields a…

Strongly Correlated Electrons · Physics 2009-10-30 J. H. Han

A many-body Green's function approach to the microscopic theory of plasmon-enhanced spectroscopy is presented within the context of localized surface-plasmon resonance spectroscopy and applied to investigate the coupling between…

Chemical Physics · Physics 2015-05-14 David J. Masiello , George C. Schatz

We present an overview of electronic device modeling using non-equilibrium Green function techniques. The basic approach developed in the early 1970s has become increasingly popular during the last 10 years. The rise in popularity was…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Roger K. Lake , Rajeev R. Pandey

A simple model of noninteracting electrons with a separable one-body potential is used to discuss the possible pole structure of single particle Green's functions for fermions on unphysical sheets in the complex frequency plane as a…

Strongly Correlated Electrons · Physics 2009-10-30 K. Schoenhammer

We derive equations of motion for higher order density response functions using the theory of thermodynamic Green's functions. We also derive expressions for the higher order generalized dielectric functions and polarization functions.…

Strongly Correlated Electrons · Physics 2024-10-04 Jan Vorberger , Tobias Dornheim , Maximilian P. Böhme , Zhandos Moldabekov , Panagiotis Tolias

Computationally inexpensive approximations describing electron-phonon scattering in molecular-scale conductors are derived from the non-equilibrium Green's function method. The accuracy is demonstrated with a first principles calculation on…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Magnus Paulsson , Thomas Frederiksen , Mads Brandbyge
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