Nonlocal orbital-free kinetic pressure tensors for the Fermi gas

Palade, D. I.

doi:10.1103/physrevb.98.245401

Cited by 11 publications

(5 citation statements)

References 48 publications

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“…The function J pp contains the correlations of the fluctuations of the momentum field. Another formulation of the QHD equations, that is closer to classical hydrodynamics, is obtained if, instead of the mean orbital density n and the mean momentum p, we consider the density n(r, t) and the current density j(r, t), defined in terms of the orbital quantities n i and j i = n i v i , as [86,230] n(r, t) = 2…”

Section: Derivation Of the Qhd Equations From Mqhdmentioning

confidence: 99%

Ab initio simulation of warm dense matter

et al. 2020

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Warm dense matter (WDM) -an exotic state of highly compressed matter -has attracted high interest in recent years in astrophysics and for dense laboratory systems. At the same time, this state is extremely difficult to treat theoretically. This is due to the simultaneous appearance of quantum degeneracy, Coulomb correlations and thermal effects, as well as the overlap of plasma and condensed phases. Recent breakthroughs are due to the successful application of density functional theory (DFT) methods which, however, often lack the necessary accuracy and predictive capability for WDM applications. The situation has changed with the availability of the first ab initio data for the exchange-correlation free energy of the warm dense uniform electron gas (UEG) that were obtained by quantum Monte Carlo (QMC) simulations, for recent reviews, see Dornheim et al., Phys. Plasmas 24, 056303 (2017) and Phys. Rep. 744, 1-86 (2018). In the present article we review recent further progress in QMC simulations of the warm dense UEG: namely, ab initio results for the static local field correction G(q) and for the dynamic structure factor S(q, ω). These data are of key relevance for the comparison with x-ray scattering experiments at free electron laser facilities and for the improvement of theoretical models.In the second part of this paper we discuss simulations of WDM out of equilibrium. The theoretical approaches include Born-Oppenheimer molecular dynamics, quantum kinetic theory, timedependent DFT and hydrodynamics. Here we analyze strengths and limitations of these methods and argue that progress in WDM simulations will require a suitable combination of all methods. A particular role might be played by quantum hydrodynamics, and we concentrate on problems, recent progress, and possible improvements of this method.

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Section: Derivation Of the Qhd Equations From Mqhdmentioning

confidence: 99%

Ab initio simulation of warm dense matter

et al. 2020

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“…where C s and C d represent static and dynamic corrections, respectively. Although some schemes have been proposed [40,67,85], the first-principle derivation of dynamic corrections presents fundamental challenges, especially for finite-size systems. In this article, we consider only static corrections, in particular at the Laplacianlevel, where the KE has the form:…”

Section: Pauli-gaussian and Laplacian-level Functionals In Quantum Hy...mentioning

confidence: 99%

“…We derive the Laplacian-level QHT linear-response equations in the frequency-domain: this is a completely novel implementation for the QHT, so far only limited to the TFλvW KE functionals. Note that Laplacianlevel KE functionals are much simpler than fully nonlocal functional based on the Lindhard response in the reciprocal space [30,85,86] and can be easily applied to finite systems [87]. We demonstrate that in the QHT-PGSL approach, only the main plasmon peak appears in the absorption spectrum, which is stable to the changes of computational domain size.…”

Section: Introductionmentioning

confidence: 96%

“…iii) The TFλvW functional is known to be quite a rough approximation to the exact KE, and different limitations of this functional have been shown in different contexts, e.g., lack of dynamical corrections [40,55,65,85] and incorrect response for homogeneous electron gas [30,86,87]. Thus, the great accuracy of QHT calculations with the TFλvW functional obtained in some cases should be related to some error cancellation and, therefore, cannot have general validity.…”

Section: Introductionmentioning

confidence: 99%

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Laplacian-Level Quantum Hydrodynamic Theory for Plasmonics

Baghramyan,

Della Sala,

Ciracì

2020

Preprint

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An accurate description of the optical response of subwavelength metallic particles and nanogap structures is a key problem of plasmonics. Quantum hydrodynamic theory (QHT) has emerged as a powerful method to calculate the optical response of metallic nanoparticles since it takes into account nonlocality and spill-out effects. Nevertheless, the absorption spectra of metallic particles from QHT is affected, at energies higher than the main plasmon peak, by several additional peaks, which are instead largely damped in reference time-dependent density-functional theory calculations. Moreover, we show here that these peaks have a strong dependence on the simulation domain-size so that the numerical convergence of QHT calculations is problematic. In this article, we introduce a QHT method accounting for kinetic energy contributions depending on the Laplacian of the electronic density, thus beyond the gradient-only dependence of conventional QHT. In this way, only the main plasmon peak is obtained, with a numerically stable absorption spectrum and more accurate intensities of the plasmon peak. Thus, the Laplacian-level QHT represents a novel, efficient and accurate platform to study plasmonic systems.

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“…VI. derived from the KS equations in TD-DFT [26,44]. In this work, we restrict the discussion to the stationary properties and linear optical responses.…”

Section: Introductionmentioning

confidence: 99%

Calibrating quantum hydrodynamic model for noble metals in nanoplasmonics

Zhang¹,

Li²,

He³

et al. 2021

Preprint

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Quantum hydrodynamic model (QHDM) is a versatile and efficient theory for nanoplasmonics. Yet its application to noble metals hasn't been sufficiently justified, especially when electron spillover plays a significant role. Moreover no existing QHDM has been specially devised to treat metal in a dielectric environment. In a recent work [in preparation], we developed a refined QHDM, where the near-field effects and static polarization of metal ion lattice, and the electron affinity and static permittivity of the dielectric are incorporated. Here we perform a careful calibration for the refined QHDM. The model parameters are determined by referencing (time-dependent) density functional theory calculations for special cases of simple metal. Overall quite satisfactory agreement is achieved. The predictive power of the calibrated QHDM is further demonstrated with gold nanomatryoshkas. We expect the well-calibrated refined QHDM would provide the nanoplasmonics community with a useful tool.

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Nonlocal orbital-free kinetic pressure tensors for the Fermi gas

Cited by 11 publications

References 48 publications

Ab initio simulation of warm dense matter

Ab initio simulation of warm dense matter

Laplacian-Level Quantum Hydrodynamic Theory for Plasmonics

Calibrating quantum hydrodynamic model for noble metals in nanoplasmonics

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