Disorder and interactions in systems out of equilibrium: The exact independent-particle picture from density functional theory

Karlsson, Daniel; Hopjan, Miroslav; Verdozzi, Claudio

doi:10.1103/physrevb.97.125151

Cited by 16 publications

(14 citation statements)

References 76 publications

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“…If perturbation theory could be applied, i.e., when the interaction is weak, current correlation or noise simulations are still feasible to perform in terms of the one-particle Green’s function [ 76 , 77 , 78 , 79 , 80 , 81 ]. Disordered interacting systems have also been studied using mean-field or density-functional theories [ 82 , 83 , 84 ]. Here, out-of-equilibrium dynamics only due to voltage bias was considered but also thermal gradients could be included similarly [ 46 , 85 , 86 , 87 , 88 ].…”

Section: Discussionmentioning

confidence: 99%

Electron Traversal Times in Disordered Graphene Nanoribbons

Ridley¹,

Sentef²,

Tuovinen³

2019

Entropy

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Using the partition-free time-dependent Landauer-Büttiker formalism for transient current correlations, we study the traversal times taken for electrons to cross graphene nanoribbon (GNR) molecular junctions. We demonstrate electron traversal signatures that vary with disorder and orientation of the GNR. These findings can be related to operational frequencies of GNR-based devices and their consequent rational design. arXiv:1906.12129v1 [cond-mat.mes-hall]

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Section: Discussionmentioning

confidence: 99%

Electron Traversal Times in Disordered Graphene Nanoribbons

Ridley¹,

Sentef²,

Tuovinen³

2019

Entropy

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“…In addition to ab initio descriptions of matter, (TD)DFT has been applied to model Hamiltonians to explore conceptual and methodological aspects of the theory [39][40][41][42][43][44][45][46][47][48][49][50][51], as well as for specific applications to cold atoms [52][53][54][55], Kondo physics [56][57][58], quantum transport [59][60][61], quantum electrodynamics [33], and nonequilibrium thermodynamics [62], to mention a few [63]. We here consider a two-component DFT for the HH model, where the basic variables are given by the set (n, x) ≡ ({n i }, {x i }), with n i = n i↑ + n i↓ being the total electron density at site i, and the conjugated fields are (v, η) ≡ ({v i }, {η i }).…”

Section: Density Functional Theorymentioning

confidence: 99%

Electron-electron versus electron-phonon interactions in lattice models: Screening effects described by a density functional theory approach

Boström

Helmer

Werner

et al. 2019

Phys. Rev. Research

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We address the interplay of electron-electron (e-e) and electron-phonon (e-ph) interactions in the Hubbard-Holstein model, using a two-component density functional theory. Exchange-correlation potentials constructed via dynamical mean field theory for a D = ∞ Bethe lattice and analytically for an isolated site give a new perspective on e-ph screening of the e-e interactions and its effect on the charge-and spin-Kondo regimes. Comparisons to exact benchmarks show that the approach is suitable to describe transport properties and realtime dynamics in homogeneous and inhomogeneous lattice systems.

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“…However, one of our longer term aims is to use our scheme (for skyrmions and other magnetic phenomena) in realistic materials. Based on our experience with double‐time NEGF, this is when correlations (even weak ones) do in fact play a role, and need to be accounted for via self‐energies contributions, determined, for example, via many‐body approximations. In this case, for large systems and many orbitals, double‐time NEGF can rapidly become computationally expensive, and simplified schemes can gain prominence.…”

Section: Introductionmentioning

confidence: 99%

Steering Magnetic Skyrmions with Currents: A Nonequilibrium Green's Functions Approach

Boström

Verdozzi

2019

Physica Status Solidi (b)

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Magnetic skyrmions, topologically protected vortex-like configurations in spin textures, are of wide conceptual and practical appeal, notably in relation to the making of so-called race-track memory devices. Skyrmions can be created, steered, and destroyed with magnetic fields and/or (spin) currents.Here the authors focus on the latter mechanism, analyzed via a microscopic treatment of the skyrmion-current interaction. The system considered is an isolated skyrmion in a square-lattice cluster, interacting with electron spins in a current-carrying quantum wire. For the theoretical description, a quantum formulation of spin-dependent currents via nonequilibrium Green's functions (NEGF) within the generalized Kadanoff-Baym ansatz (GKBA) is employed. This is combined with a treatment of skyrmions based on classical localized spins, with the skyrmion motion described via Ehrenfest dynamics. With the mixed quantum-classical scheme, the authors assess how time-dependent currents can affect the skyrmion dynamics, and how this in turn depends on electron-electron and spin-orbit interactions in the wire. This study shows the usefulness of a quantum-classical treatment of skyrmion steering via currents, as a way for example to validate/extract an effective, classical-only, description of skyrmion dynamics from a microscopic quantum modeling of the skyrmion-current interaction.

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Disorder and interactions in systems out of equilibrium: The exact independent-particle picture from density functional theory

Cited by 16 publications

References 76 publications

Electron Traversal Times in Disordered Graphene Nanoribbons

Electron Traversal Times in Disordered Graphene Nanoribbons

Electron-electron versus electron-phonon interactions in lattice models: Screening effects described by a density functional theory approach

Steering Magnetic Skyrmions with Currents: A Nonequilibrium Green's Functions Approach

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