English
Related papers

Related papers: Conserving approximations in time-dependent quantu…

200 papers

We present quantum electron transport theory that incorporates dynamical effects of motion of atoms on electrode-molecule interfaces in the calculations of the electric current. The theory is based on non-equilibrium Green's functions. We…

Mesoscale and Nanoscale Physics · Physics 2018-08-14 Vincent F. Kershaw , Daniel S. Kosov

The Kadanoff-Baym equations (KBE) are usually derived under the assumption of the weakening of initial correlations (Bogolyubov's condition) and, therefore, fail to correctly describe the short time behavior. We demonstrate that this…

Statistical Mechanics · Physics 2017-08-23 D. Kremp , D. Semkat , M. Bonitz

In this paper, the exact transient quantum transport of non-interacting nanostructures is investigated in the presence of initial system-lead correlations and initial lead-lead correlations for a device system coupled to general electronic…

Mesoscale and Nanoscale Physics · Physics 2015-10-07 Pei-Yun Yang , Chuan-Yu Lin , Wei-Min Zhang

The nonequilibrium dynamics of quantum fields is an initial-value problem, which can be described by Kadanoff-Baym equations. Typically, and in particular when numerical solutions are demanded, these Kadanoff-Baym equations are restricted…

High Energy Physics - Phenomenology · Physics 2009-12-01 Mathias Garny , Markus Michael Muller

We lay down the {\em ab initio} many-body quantum theory of electrons and phonons in- and out-of-equilibrium at any temperature. We begin by addressing a fundamental issue concerning the {\em ab initio} Hamiltonian in the harmonic…

Materials Science · Physics 2024-02-19 Gianluca Stefanucci , Robert van Leeuwen , Enrico Perfetto

The Kadanoff-Baym (KB) equations are solved numerically for infinite nuclear matter. In particular we calculate correlation energies and correlation times. Approximating the Green's functions in the KB collision kernel by the free Green's…

Nuclear Theory · Physics 2009-11-07 H. S. Köhler , K. Morawetz

Non-equilibrium Green's function theory for non-adiabatic effects in quantum transport [Kershaw and Kosov, J.Chem. Phys. 2017, 147, 224109 and J. Chem. Phys. 2018, 149, 044121] is extended to the case of interacting electrons. We consider a…

Mesoscale and Nanoscale Physics · Physics 2019-02-20 Vincent F. Kershaw , Daniel S. Kosov

We review one of the most versatile theoretical approaches to the study of time-dependent correlated quantum transport in nano-systems: the non-equilibrium Green's function (NEGF) formalism. Within this formalism, one can treat, on the same…

Mesoscale and Nanoscale Physics · Physics 2022-06-27 M. Ridley , N. W. Talarico , D. Karlsson , N. Lo Gullo , R. Tuovinen

We study transport through an interacting model system consisting of a central correlated site coupled to finite bandwidth tight-binding leads, which are considered as effectively noninteracting. Its nonequilibrium properties are determined…

Mesoscale and Nanoscale Physics · Physics 2011-06-29 A. -M. Uimonen , E. Khosravi , G. Stefanucci , S. Kurth , R. van Leeuwen , E. K. U. Gross

The non-equilibrium Green's function gives access to one-body observables for quantum systems. Of particular interest are quantities such as density, currents, and absorption spectra which are important for interpreting experimental results…

Computational Physics · Physics 2025-05-02 Thomas Blommel , David J. Gardner , Carol S. Woodward , Emanuel Gull

The ubiquitous effects of the environment on quantum-mechanical systems generally cause temporally correlated fluctuations. This particularly holds for systems of interest for quantum computation where such effects lead to correlated…

Quantum Physics · Physics 2025-04-23 Balázs Gulácsi , Guido Burkard

Many-body quantum systems in nonequilibrium remain one of the frontiers of many-body physics. While there has been significant advances in describing the short-time evolution of these systems using a variety of different numerical…

Quantum Physics · Physics 2021-01-05 Herbert F. Fotso , Eric Dohner , Alexander Kemper , James K. Freericks

We consider a quantum dot, affected by a local vibrational mode and contacted to macroscopic leads, in the non-equilibrium steady-state regime. We apply a variational Lang-Firsov transformation and solve the equations of motion of the Green…

Strongly Correlated Electrons · Physics 2015-05-28 T. Koch , J. Loos , A. Alvermann , H. Fehske

One of the challenges in diagrammatic simulations of nonequilibrium phenomena in lattice models is the large memory demand for storing momentum-dependent two-time correlation functions. This problem can be overcome with the recently…

Strongly Correlated Electrons · Physics 2025-10-23 Maksymilian Środa , Ken Inayoshi , Hiroshi Shinaoka , Philipp Werner

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

We present a quantum kinetic approach for the time-resolved description of many-body effects in photoionization processes in atoms. The method is based on the non-equilibrium Green functions formalism and solves the Keldysh/Kadanoff-Baym…

Atomic Physics · Physics 2015-05-13 D. Hochstuhl , K. Balzer , S. Bauch , M. Bonitz

We consider nonequilibrium transport in a simple chain of identical mechanical cells in which particles move around. In each cell, there is a rotating disc, with which these particles interact, and this is the only interaction in the model.…

Statistical Mechanics · Physics 2008-07-15 Jean-Pierre Eckmann , Carlos Mejia-Monasterio , Emmanuel Zabey

We have implemented time-propagation of the non-equilibrium Green function for atoms and molecules, by solving the Kadanoff-Baym equations within a conserving self-energy approximation. We here demonstrate the usefulnes of time-propagation…

Materials Science · Physics 2007-05-23 Nils Erik Dahlen , Robert van Leeuwen

The traditional approach to studying near-field thermal transfer is based on fluctuational electrodynamics. However, this approach may not be suitable for nonequilibrium states due to dynamic drivings. In our work, we introduce a…

Mesoscale and Nanoscale Physics · Physics 2024-02-26 Gaomin Tang , Jian-Sheng Wang

The time-dependent transport through a nano-scale device, consisting of a single spin-degenerate orbital with on-site Coulomb interaction, coupled to two leads, is investigated. Various gate and bias voltage time-dependences are considered.…

Mesoscale and Nanoscale Physics · Physics 2014-06-30 V. Vovchenko , D. Anchishkin , J. Azema , P. Lombardo , R. Hayn , A. -M. Daré