Density functional description of Coulomb blockade: Adiabatic versus dynamic exchange correlation

Liu, Fulai; Burke, Kieron

doi:10.1103/physrevb.91.245158

Cited by 12 publications

(9 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We emphasize that this polarization is not physically correct as the system has unpolarized leads -hence the chemical potentials for both spin directions are identical. However, it has been pointed out by several researchers that the spin-polarized states found in DFT calculations can give us valuable information about the levels and their occupation 11,[44][45][46] .…”

Section: Image Charge Effects For Benzenediamine (Bda)mentioning

confidence: 99%

Image effects in transport at metal-molecule interfaces

Verzijl

Gil

Perrin

et al. 2015

The Journal of Chemical Physics

View full text Add to dashboard Cite

We present a method for incorporating image-charge effects into the description of charge transport through molecular devices. A simple model allows us to calculate the adjustment of the transport levels, due to the polarization of the electrodes as charge is added to and removed from the molecule. For this, we use the charge distributions of the molecule between two metal electrodes in several charge states, rather than in gas phase, as obtained from a density-functional theory-based transport code. This enables us to efficiently model level shifts and gap renormalization caused by image-charge effects, which are essential for understanding molecular transport experiments. We apply the method to benzene di-amine molecules and compare our results with the standard approach based on gas phase charges. Finally, we give a detailed account of the application of our approach to porphyrin-derivative devices recently studied experimentally by Perrin et al. [Nat. Nanotechnol. 8, 282 (2013)], which demonstrates the importance of accounting for image-charge effects when modeling transport through molecular junctions.

show abstract

Section: Image Charge Effects For Benzenediamine (Bda)mentioning

confidence: 99%

Image effects in transport at metal-molecule interfaces

Verzijl

Gil

Perrin

et al. 2015

The Journal of Chemical Physics

View full text Add to dashboard Cite

show abstract

“…The electronic transport has also been studied by applying SOFT to the Anderson junction model [46][47][48]. Time-dependent [49][50][51] and temperature-dependent extensions [52,53] have been investigated over the years.…”

Section: Introductionmentioning

confidence: 99%

Site-occupation embedding theory using Bethe ansatz local density approximations

et al. 2018

View full text Add to dashboard Cite

Site-occupation embedding theory (SOET) is an alternative formulation of density-functional theory (DFT) for model Hamiltonians where the fully-interacting Hubbard problem is mapped, in principle exactly, onto an impurity-interacting (rather than a non-interacting) one. It provides a rigorous framework for combining wavefunction (or Green function) based methods with DFT. In this work, exact expressions for the per-site energy and double occupation of the uniform Hubbard model are derived in the context of SOET. As readily seen from these derivations, the so-called bath contribution to the per-site correlation energy is, in addition to the latter, the key densityfunctional quantity to model in SOET. Various approximations based on Bethe ansatz and perturbative solutions to the Hubbard and single impurity Anderson models are constructed and tested on a one-dimensional ring. The self-consistent calculation of the embedded impurity wavefunction has been performed with the density matrix renormalization group method. It has been shown that promising results are obtained in specific regimes of correlation and density. Possible further developments have been proposed in order to provide reliable embedding functionals and potentials. * Corresponding author; senjean@unistra.fr for which DMFT is not sufficiently accurate, especially in the case when non local electron correlation becomes important. In order to further improve on its performance, combined DMFT+DFT [13] or DMFT+GW [14-19] schemes have been proposed to recover such effects. In another promising approach, the so-called selfenergy embedding theory [20][21][22], strong correlation is not considered as strictly local, which can be appreciable for real compounds. Its applicability to both model and ab-initio Hamiltonians is also appealing. All these embedding techniques are formulated in terms of the (frequency-dependent) one-particle Green function. On the other hand, in the density-matrix embedding theory (DMET) [23][24][25][26][27][28][29], the embedded fragment (impurity) is described with a high-level wavefunction-based method while the rest of the system is usually treated at the mean-field level. Extensions have been proposed in order to include correlation in the bath [30] or for improving the description of the boundary between the fragment and the bath [31].Turning to DFT, its extension to model Hamiltonians is usually referred to as site-occupation functional theory (SOFT) [32][33][34][35]. In conventional Kohn-Sham (KS) SOFT, the physical fully-interacting many-body problem is mapped onto a noninteracting one by means of a Hartree-exchange-correlation (Hxc) functional of the density (i.e., the sites occupation in this context). The SOFT has been shown to give very accurate density and energy profiles with the Bethe ansatz local density approximation (BALDA) [36][37][38], the spin-dependent BALDA [39], and its fully numerical formulation [40,41]. The methods have been applied to both repulsive [42,43] and attractive [44,45] Hubbard models. arXiv:1710....

show abstract

“…when both sites are half-filled) in the strongly correlated limit (U/t → +∞). A similar discontinuity can be observed in the Anderson junction model [55][56][57]. It can be interpreted as follows: the impurity site with occupation n is an open system and, in order to let n vary continuously from 0 to 1, we need a grand canonical ensemble consisting of degenerate zero-and one-electron states.…”

Section: Embedded Impurity Systemmentioning

confidence: 63%

Local density approximation in site-occupation embedding theory

et al. 2016

View full text Add to dashboard Cite

Site-occupation embedding theory (SOET) is a density-functional theory (DFT)-based method which aims at modelling strongly correlated electrons. It is in principle exact and applicable to model and quantum chemical Hamiltonians. The theory is presented here for the Hubbard Hamiltonian. In contrast to conventional DFT approaches, the site (or orbital) occupations are deduced in SOET from a partially-interacting system consisting of one (or more) impurity site(s) and non-interacting bath sites. The correlation energy of the bath is then treated implicitly by means of a site-occupation functional. In this work, we propose a simple impurity-occupation functional approximation based on the two-level (2L) Hubbard model which is referred to as two-level impurity local density approximation (2L-ILDA). Results obtained on a prototypical uniform 8-site Hubbard ring are promising. The extension of the method to larger systems and more sophisticated model Hamiltonians is currently in progress.

show abstract

Density functional description of Coulomb blockade: Adiabatic versus dynamic exchange correlation

Cited by 12 publications

References 55 publications

Image effects in transport at metal-molecule interfaces

Image effects in transport at metal-molecule interfaces

Site-occupation embedding theory using Bethe ansatz local density approximations

Local density approximation in site-occupation embedding theory

Contact Info

Product

Resources

About