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Related papers: Nonequilibrium spin-boson model: from weak to stro…

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In this thesis we showed that Non-equilibrium Green's Function Perturbation Theory (NEGF) is really the overarching perturbative transport theory. This is shown in great detail by using NEGF as a starting point and developing in 3…

Mesoscale and Nanoscale Physics · Physics 2013-02-05 Meng Lee Leek

In this paper we present a general formulation for electronic transport that combines strong correlation effects with broadening and quantum coherence, and illustrate it with a simple example ("spin blockade") that clearly demonstrates all…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Supriyo Datta

Employing the non-perturbative numerical renormalization group method, we study the dynamics of the spin-boson model, which describes a two-level system coupled to a bosonic bath with spectral density J(omega) propto omega^s. We show that,…

Statistical Mechanics · Physics 2007-06-13 Frithjof B. Anders , Ralf Bulla , Matthias Vojta

We apply the Nonequilibrium Green's Function (NEGF) formalism to the problem of a multi-terminal nanojunction subject to an arbitrary time-dependent bias. In particular, we show that taking a generic one-particle system Hamiltonian within…

Mesoscale and Nanoscale Physics · Physics 2014-12-16 Michael Ridley , Angus MacKinnon , Lev Kantorovich

We follow the nonequilibrium Green's function formalism to study time-dependent thermal transport in a linear chain system consisting of two semi-infinite leads connected together by a coupling that is harmonically modulated in time. The…

Mesoscale and Nanoscale Physics · Physics 2010-08-18 Eduardo C. Cuansing , Jian-Sheng Wang

A new approximate computational framework is proposed for computing the non-equilibrium charge density in the context of the non-equilibrium Green's function (NEGF) method for quantum mechanical transport problems. The framework consists of…

Computational Physics · Physics 2015-05-20 Quan Chen , Jun Li , Chiyung Yam , Yu Zhang , Ngai Wong , Guanhua Chen

We have recently proposed a Nonequilibrium Green's Function (NEGF) approach to include Auger decay processes in the ultrafast charge dynamics of photoionized molecules. Within the so called Generalized Kadanoff-Baym Ansatz the fundamental…

Other Condensed Matter · Physics 2018-10-17 F. Covito , E. Perfetto , A. Rubio , G. Stefanucci

Nonequilibrium electronic transport through a quantum dot coupled to ferromagnetic leads (electrodes) is studied theoretically by the nonequilibrium Green function technique. The system is described by the Anderson model with arbitrary…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 R. Swirkowicz , M. Wilczynski , J. Barnas

We present a detailed treatment of the nonequilibrium Green's function method for thermal transport due to atomic vibrations in nanostructures. Some of the key equations, such as self-energy and conductance with nonlinear effect, are…

Statistical Mechanics · Physics 2011-11-09 Jian-Sheng Wang , Nan Zeng , Jian Wang , Chee Kwan Gan

Quantum energy transfer in a chain of two-level (spin) units, connected at its ends to two thermal reservoirs, is analyzed in two limits: (i) In the off-resonance regime, when the characteristic subsystem excitation energy gaps are larger…

Mesoscale and Nanoscale Physics · Physics 2015-05-28 Claire X. Yu , Lian-Ao Wu , Dvira Segal

We present a method which uses density functional theory (DFT) to treat transport through a single molecule connected to two conducting leads for the weak and intermediate coupling. This case is not accessible to standard non-equilibrium…

Mesoscale and Nanoscale Physics · Physics 2011-01-21 Fatemeh Mirjani , Joseph M. Thijssen

We extend a non local and non covariant version of the Thirring model in order to describe a many-body system with spin-flipping interactions By introducing a model with two fermion species we are able to avoid the use of non abelian…

High Energy Physics - Theory · Physics 2016-08-15 Aníbal Iucci , Kang Li , Carlos M. Naón

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

We present a combined theoretical approach to study the nonequilibrium transport properties of nanoscale systems coupled to metallic electrodes and exhibiting strong electron-phonon interactions. We use the Keldysh Green function formalism…

Mesoscale and Nanoscale Physics · Physics 2015-05-20 R. C. Monreal , F. Flores , A. Martin-Rodero

The concept of transmission eigenchannels is described in a tight-binding nonequilibrium Green's function (NEGF) framework. A simple procedure for calculating the eigenchannels is derived using only the properties of the device subspace and…

Mesoscale and Nanoscale Physics · Physics 2011-11-09 Magnus Paulsson , Mads Brandbyge

Out-of-equilibrium behavior is explored in the one-dimensional anisotropic $XY$ model. Initially preparing the system in the isotropic $XX$ model with a linearly varying magnetic field to create a domain-wall magnetization profile, dynamics…

Quantum Gases · Physics 2016-05-20 Jarrett L. Lancaster

We propose a scheme for the quantum simulation of sub-Ohmic spin--boson models by color centers in free-standing hexagonal boron nitride (h-BN) membranes. The electronic spin of a color center that couples to the membrane vibrational…

Quantum Physics · Physics 2018-10-31 Mehdi Abdi , Martin B. Plenio

The spin-boson model, describing a two-level system coupled to a bath of harmonic oscillators, is a generic model for quantum dissipation, with manifold applications. It has also been studied as a simple example for an impurity quantum…

Statistical Mechanics · Physics 2014-12-24 Benedikt Bruognolo , Andreas Weichselbaum , Cheng Guo , Jan von Delft , Imke Schneider , Matthias Vojta

We investigate numerically the magnetisation dynamics of an array of nano-disks interacting through the magneto-dipolar coupling. In the presence of a temperature gradient, the chain reaches a non-equilibrium steady state where energy and…

Statistical Mechanics · Physics 2015-03-03 Simone Borlenghi , Stefano Iubini , Stefano Lepri , Jonathan Chico , Lars Bergqvist , Anna Delin , Jonas Fransson

Recent experiments in hybrid-quantum systems facilitate the potential realization of one of the most fundamental interacting Hamiltonian-Reservoir system, namely, the single-site Bose-Hubbard model coupled to two reservoirs at different…

Quantum Physics · Physics 2017-01-02 Archak Purkayastha , Abhishek Dhar , Manas Kulkarni