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dc.contributor.authorD'Agosta, Robertoeng
dc.contributor.authorDi Ventra, Massimilianoeng
dc.contributor.authorVignale, Giovanni, 1957-eng
dc.date.issued2007eng
dc.descriptionURL:http://link.aps.org/doi/10.1103/PhysRevB.76.035320 DOI:10.1103/PhysRevB.76.035320eng
dc.description.abstractIn the local-density approximation (LDA) for electronic time-dependent current-density-functional theory, many-body effects are described in terms of the viscoelastic constants of the homogeneous three-dimensional electron gas. In this paper, we critically examine the applicability of the three-dimensional LDA to the calculation of the viscous damping of one-dimensional collective oscillations of angular frequency ω in a quasi-two-dimensional quantum well. We calculate the effective viscosity ζ(ω) from perturbation theory in the screened Coulomb interaction and compare it with the commonly used three-dimensional LDA viscosity Y(ω). Significant differences are found. At low frequency, Y(ω) is dominated by a shear term, which is absent in ζ(ω). At high frequency, ζ(ω) and Y(ω) exhibit different power-law behaviors (ω−3 and ω−5∕2, respectively), reflecting different spectral densities of electron-hole excitations in two and three dimensions. These findings demonstrate the need for better approximations for the exchange-correlation stress tensor in specific systems where the use of the three-dimensional functionals may lead to unphysical results.eng
dc.description.sponsorshipR.D. thanks C. Ullrich for his assistance with part of the numerical calculations. R.D. and M.D.V. acknowledge financial support from the Department of Energy Grant No. DE-FG02-05ER46204. G.V. acknowledges financial support from the Department of Energy Grant No. DE-FG02-05ER46203.eng
dc.identifier.citationPhys. Rev. B 76, 035320 (2007) [9 pages]eng
dc.identifier.issn1098-0121eng
dc.identifier.urihttp://hdl.handle.net/10355/7729eng
dc.languageEnglisheng
dc.publisherAmerican Physical Societyeng
dc.relation.ispartofcollectionUniversity of Missouri--Columbia. College of Arts and Sciences. Department of Physics and Astronomy. Physics and Astronomy publicationseng
dc.subjectelectron states at surfaces and interfaceseng
dc.subjectlocal density approximationeng
dc.subjectgradient and other correctionseng
dc.subject.lcshQuantum wellseng
dc.subject.lcshCollective excitationseng
dc.subject.lcshElectron configurationeng
dc.subject.lcshInterfaces (Physical sciences)eng
dc.subject.lcshDensity functionalseng
dc.subject.lcshDensityeng
dc.subject.lcshApproximation theoryeng
dc.subject.lcshConjugate gradient methodseng
dc.titleElectronic viscosity in a quantum well: A test for the local-density approximationeng
dc.typeArticleeng


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