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Tuovinen R, van Leeuwen R, Perfetto E, Stefanucci G. Electronic transport in molecular junctions: The generalized Kadanoff-Baym ansatz with initial contact and correlations. J Chem Phys 2021; 154:094104. [PMID: 33685185 DOI: 10.1063/5.0040685] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The generalized Kadanoff-Baym ansatz (GKBA) offers a computationally inexpensive approach to simulate out-of-equilibrium quantum systems within the framework of nonequilibrium Green's functions. For finite systems, the limitation of neglecting initial correlations in the conventional GKBA approach has recently been overcome [Karlsson et al., Phys. Rev. B 98, 115148 (2018)]. However, in the context of quantum transport, the contacted nature of the initial state, i.e., a junction connected to bulk leads, requires a further extension of the GKBA approach. In this work, we lay down a GKBA scheme that includes initial correlations in a partition-free setting. In practice, this means that the equilibration of the initially correlated and contacted molecular junction can be separated from the real-time evolution. The information about the contacted initial state is included in the out-of-equilibrium calculation via explicit evaluation of the memory integral for the embedding self-energy, which can be performed without affecting the computational scaling with the simulation time and system size. We demonstrate the developed method in carbon-based molecular junctions, where we study the role of electron correlations in transient current signatures.
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Affiliation(s)
- Riku Tuovinen
- QTF Centre of Excellence, Turku Centre for Quantum Physics, Department of Physics and Astronomy, University of Turku, 20014 Turku, Finland
| | - Robert van Leeuwen
- Department of Physics, Nanoscience Center, University of Jyväskylä, 40014 Jyväskylä, Finland
| | - Enrico Perfetto
- Dipartimento di Fisica, Università di Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy
| | - Gianluca Stefanucci
- Dipartimento di Fisica, Università di Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy
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Tuovinen R, Sentef MA, Gomes da Rocha C, Ferreira MS. Time-resolved impurity-invisibility in graphene nanoribbons. NANOSCALE 2019; 11:12296-12304. [PMID: 31211315 DOI: 10.1039/c9nr02738f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We investigate time-resolved charge transport through graphene nanoribbons supplemented with adsorbed impurity atoms. Depending on the location of the impurities with respect to the hexagonal carbon lattice, the transport properties of the system may become invisible to the impurity due to the symmetry properties of the binding mechanism. This motivates a chemical sensing device since dopants affecting the underlying sublattice symmetry of the pristine graphene nanoribbon introduce scattering. Using the time-dependent Landauer-Büttiker formalism, we extend the stationary current-voltage picture to the transient regime, where we observe how the impurity invisibility takes place at sub-picosecond time scales further motivating ultrafast sensor technology. We further characterize time-dependent local charge and current profiles within the nanoribbons, and we identify rearrangements of the current pathways through the nanoribbons due to the impurities. We finally study the behavior of the transients with ac driving which provides another way of identifying the lattice-symmetry breaking caused by the impurities.
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Affiliation(s)
- Riku Tuovinen
- Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany.
| | - Michael A Sentef
- Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany.
| | - Claudia Gomes da Rocha
- Department of Physics and Astronomy, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - Mauro S Ferreira
- School of Physics, Trinity College Dublin, Dublin 2, Ireland and Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN) and Advanced Materials and Bioengineering Research (AMBER) Centre, Trinity College Dublin, Dublin 2, Ireland
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3
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Yu W, Gao CZ, Jiang T, Zou Y, Wang JG, Wu Y, Wei B. A theoretical study of Ar 8+-acetylene collisions at 1.2 MeV: Ionization and dissociation dynamics. J Chem Phys 2019; 150:124304. [PMID: 30927893 DOI: 10.1063/1.5082729] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We theoretically study Ar8+-induced dissociation of C2H2 molecule at 1.2 MeV using the time-dependent density-functional theory non-adiabatically coupled to nuclear dynamics. We find that molecular dissociation depends strongly on the ionization at the initial stage and the collision configuration. A detailed analysis shows a correspondence between the charge state of [C2H2]q+ and the final fragments. A remarkable impact parameter effect provides deep insights of bond breakup and electronic transport. We analyze two typical sequential dissociation channels reported in experiments by tracking structural and electronic dynamics in real time. Our results provide better understanding of experiments. Moreover, the comparison between various exchange-correlation functionals reveals that electrons' correlation and self-interaction do not significantly impact the initial ionization and fragment distribution in the present study.
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Affiliation(s)
- W Yu
- Department of Nuclear Science and Technology, Institute of Modern Physics, Fudan University, Shanghai 200433, China
| | - C-Z Gao
- Institute of Applied Physics and Computational Mathematics, Beijing 100088, China
| | - T Jiang
- Department of Nuclear Science and Technology, Institute of Modern Physics, Fudan University, Shanghai 200433, China
| | - Y Zou
- Department of Nuclear Science and Technology, Institute of Modern Physics, Fudan University, Shanghai 200433, China
| | - J-G Wang
- Institute of Applied Physics and Computational Mathematics, Beijing 100088, China
| | - Y Wu
- Institute of Applied Physics and Computational Mathematics, Beijing 100088, China
| | - B Wei
- Department of Nuclear Science and Technology, Institute of Modern Physics, Fudan University, Shanghai 200433, China
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Dittmann N, Splettstoesser J, Helbig N. Nonadiabatic Dynamics in Single-Electron Tunneling Devices with Time-Dependent Density-Functional Theory. PHYSICAL REVIEW LETTERS 2018; 120:157701. [PMID: 29756889 DOI: 10.1103/physrevlett.120.157701] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 11/28/2017] [Indexed: 06/08/2023]
Abstract
We simulate the dynamics of a single-electron source, modeled as a quantum dot with on-site Coulomb interaction and tunnel coupling to an adjacent lead in time-dependent density-functional theory. Based on this system, we develop a time-nonlocal exchange-correlation potential by exploiting analogies with quantum-transport theory. The time nonlocality manifests itself in a dynamical potential step. We explicitly link the time evolution of the dynamical step to physical relaxation timescales of the electron dynamics. Finally, we discuss prospects for simulations of larger mesoscopic systems.
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Affiliation(s)
- Niklas Dittmann
- Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, SE-41298 Göteborg, Sweden
- Institute for Theory of Statistical Physics, RWTH Aachen, 52056 Aachen, Germany
- Peter-Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Janine Splettstoesser
- Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, SE-41298 Göteborg, Sweden
| | - Nicole Helbig
- Peter-Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich, 52425 Jülich, Germany
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Gritsenko O. Charge-transfer (CT) orbitals for the one-electron description of CT excitations in a wide range of donor-acceptor separations. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2016.11.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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6
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Wang F, Yao Y, Calvayrac F, Zhang F. Extraction of state-resolved information from systems with a fractional number of electrons within the framework of time-dependent density functional theory. J Chem Phys 2016. [DOI: 10.1063/1.4962908] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Affiliation(s)
- Feng Wang
- School of Physics, Beijing Institute of Technology, Beijing 100081, China
| | - Yugui Yao
- School of Physics, Beijing Institute of Technology, Beijing 100081, China
| | - Florent Calvayrac
- Institut des Molecules et Matériaux du Mans UMR 6283, Université du Maine, LUNAM 72085 Le Mans Cedex 9, France
| | - Fengshou Zhang
- The Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875, China
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Mirtschink A, Seidl M, Gori-Giorgi P. Derivative discontinuity in the strong-interaction limit of density-functional theory. PHYSICAL REVIEW LETTERS 2013; 111:126402. [PMID: 24093282 DOI: 10.1103/physrevlett.111.126402] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Indexed: 06/02/2023]
Abstract
We generalize the exact strong-interaction limit of the exchange-correlation energy of Kohn-Sham density functional theory to open systems with fluctuating particle numbers. When used in the self-consistent Kohn-Sham procedure on strongly interacting systems, this functional yields exact features crucial for important applications such as quantum transport. In particular, the steplike structure of the highest-occupied Kohn-Sham eigenvalue is very well captured, with accurate quantitative agreement with exact many-body chemical potentials. While it can be shown that a sharp derivative discontinuity is present only in the infinitely strongly correlated limit, at finite correlation regimes we observe a slightly smoothened discontinuity, with qualitative and quantitative features that improve with increasing correlation. From the fundamental point of view, our results obtain the derivative discontinuity without making the assumptions used in its standard derivation, offering independent support for its existence.
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Affiliation(s)
- André Mirtschink
- Department of Theoretical Chemistry and Amsterdam Center for Multiscale Modeling, FEW, Vrije Universiteit, De Boelelaan 1083, 1081HV Amsterdam, Netherlands
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Baerends EJ, Gritsenko OV, van Meer R. The Kohn–Sham gap, the fundamental gap and the optical gap: the physical meaning of occupied and virtual Kohn–Sham orbital energies. Phys Chem Chem Phys 2013; 15:16408-25. [DOI: 10.1039/c3cp52547c] [Citation(s) in RCA: 307] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Ramsden JD, Godby RW. Exact density-functional potentials for time-dependent quasiparticles. PHYSICAL REVIEW LETTERS 2012; 109:036402. [PMID: 22861876 DOI: 10.1103/physrevlett.109.036402] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Indexed: 06/01/2023]
Abstract
We calculate the exact Kohn-Sham potential that describes, within time-dependent density-functional theory, the propagation of an electron quasiparticle wave packet of nonzero crystal momentum added to a ground-state model semiconductor. The potential is observed to have a highly nonlocal functional dependence on the charge density, in both space and time, giving rise to features entirely lacking in local or adiabatic approximations. The dependence of the nonequilibrium part of the Kohn-Sham electric field on the local current and charge density is identified as a key element of the correct Kohn-Sham functional.
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Affiliation(s)
- J D Ramsden
- Department of Physics, University of York and European Theoretical Spectroscopy Facility (ETSF), Heslington, York YO10 5DD, United Kingdom
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Song P, Nordlander P, Gao S. Quantum mechanical study of the coupling of plasmon excitations to atomic-scale electron transport. J Chem Phys 2011; 134:074701. [DOI: 10.1063/1.3554420] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Gál T, Geerlings P. Energy surface, chemical potentials, Kohn–Sham energies in spin-polarized density functional theory. J Chem Phys 2010; 133:144105. [DOI: 10.1063/1.3467898] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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13
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Vieira D, Capelle K. Investigation of Self-Interaction Corrections for an Exactly Solvable Model System: Orbital Dependence and Electron Localization. J Chem Theory Comput 2010; 6:3319-29. [DOI: 10.1021/ct100352r] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Daniel Vieira
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Santo André, 09210-170 São Paulo, Brazil
| | - K. Capelle
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Santo André, 09210-170 São Paulo, Brazil
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