The Experts below are selected from a list of 264 Experts worldwide ranked by ideXlab platform
Manoj K. Harbola - One of the best experts on this subject based on the ideXlab platform.
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DiffereNtial virial theorem for the fractioNal electroN Number: Derivative discoNtiNuity of the KohN-Sham exchaNge-correlatioN poteNtial
Physical Review A, 1998Co-Authors: Manoj K. HarbolaAbstract:We exteNd the differeNtial virial theorem put forth by Holas aNd March [Phys. Rev. A 51, 2040 (1995)] to a statistical mixture of deNsities correspoNdiNg to differeNt Numbers of electroNs. This allows us to derive aN expressioN for the gradieNt of the exchaNge-correlatioN poteNtial for deNsities that lead to NoNiNteger Numbers of electroNs. We apply this to study the jump iN the exchaNge-correlatioN poteNtial as the electroN Number iNcreases through aN iNteger. We show that the differeNce betweeN the gradieNt of the exchaNge-correlatioN poteNtial for $N$ electroNs, where $N$ is aN iNteger, aNd that for $N+f$ electroNs, where $f$ is a small positive Number, is similar to the electric field iN aNd arouNd a charged metal sphere: It is zero iNside, peaks at the surface, aNd theN decays. CoNsequeNtly, the correspoNdiNg poteNtial is coNstaNt iN the iNterior of the system aNd decays sharply at the surface.
David M. Ceperley - One of the best experts on this subject based on the ideXlab platform.
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ReNormalizatioN factor aNd effective mass of the two-dimeNsioNal electroN gas
Physical Review B: Condensed Matter and Materials Physics, 2009Co-Authors: Markus Holzmann, Bernard Bernu, Valerio Olevano, Richard M. Martin, David M. CeperleyAbstract:We calculate the momeNtum distributioN of the Fermi liquid phase of the homogeNeous, two-dimeNsioNal electroN gas. We show that, close to the Fermi surface, the momeNtum distributioN of a fiNite system with $N$ electroNs approaches its thermodyNamic limit slowly, with leadiNg order correctioNs scaliNg as $N^{-1/4}$. These correctioNs domiNate the extrapolatioN of the reNormalizatioN factor, $Z$, aNd the siNgle particle effective mass, $m^*$, to the iNfiNite system size. We show how coNvergeNce caN be improved aNalytically. IN the raNge $1 \le r_s \le 10$, we get a lower reNormalizatioN factor $Z$ aNd a higher effective mass, $m^*>m$, compared to the perturbative RPA values.
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reNormalizatioN factor aNd effective mass of the two dimeNsioNal electroN gas
Physical Review B, 2009Co-Authors: Markus Holzmann, Bernard Bernu, Valerio Olevano, Richard M. Martin, David M. CeperleyAbstract:We calculate the momeNtum distributioN of the Fermi-liquid phase of the homogeNeous two-dimeNsioNal electroN gas. We show that close to the Fermi surface, the momeNtum distributioN of a fiNite system with N electroNs approaches its thermodyNamic limit slowly, with leadiNg-order correctioNs scaliNg as N 1/4 . These correctioNs domiNate the extrapolatioN of the reNormalizatioN factor Z aNd the siNgle-particle effective mass m to the iNfiNite system size. We show how coNvergeNce caN be improved usiNg aNalytical correctioNs. IN the raNge 1rs10, we get a lower reNormalizatioN factor Z aNd a higher effective mass mm compared to the perturbative raNdom-phase approximatioN values. The Fermi-liquid theory of LaNdau 1 postulates a oNe-tooNe mappiNg of low-eNergy excitatioNs of aN iNteractiNg quaNtum system with that of aN ideal Fermi gas via the distributioN fuNctioN of quasiparticles of momeNtum k. The resultiNg eNergy fuNctioNal has beeN successfully applied to describe equilibrium aNd traNsport properties of quaNtum Fermi liquids: the most promiNeNt are the electroN gas aNd liquid 3 He. 2,3 However, quaNtitative microscopic calculatioNs of its basic iNgredieNts, the reNormalizatioN factor Z, aNd the effective mass m remaiN challeNgiNg. IN this Rapid CommuNicatioN, we calculate these parameters for the two-dimeNsioNal electroN gas 2DEG usiNg quaNtum MoNte Carlo QMC iN the regioN 1rs10,
Mark Van Raamsdonk - One of the best experts on this subject based on the ideXlab platform.
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quaNtum hall physics NoNcommutative field theory
Journal of High Energy Physics, 2001Co-Authors: Simeon Hellerman, Mark Van RaamsdonkAbstract:IN this Note, we study a matrix-regularized versioN of NoN-commutative U(1) CherN-SimoNs theory proposed receNtly by PolychroNakos. We determiNe a complete miNimal basis of exact wavefuNctioNs for the theory at arbitrary level k aNd raNk N. We show that these have a form highly remiNisceNt of LaughliN-type wavefuNctioNs describiNg excitatioNs of a quaNtum Hall droplet composed of N electroNs at filliNg fractioN 1/k, aNd demoNstrate explicitly that the eNergy levels aNd degeNeracies of the two theories are ideNtical. Thus, at the level of the Hilbert space, fiNite matrix CherN-SimoNs theory is ideNtical to the theory of composite fermioNs iN the lowest LaNdau level, believed to provide aN accurate descriptioN of the filliNg fractioN 1/k fractioNal quaNtum Hall state. IN the large N limit, this provides further evideNce that level k NoNcommutative U(1) CherN-SimoNs theory is equivaleNt to the LaughliN theory of the filliNg fractioN 1/k quaNtum Hall fluid, as coNjectured receNtly by SusskiNd.
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quaNtum hall physics NoNcommutative field theory
arXiv: High Energy Physics - Theory, 2001Co-Authors: Simeon Hellerman, Mark Van RaamsdonkAbstract:IN this Note, we study a matrix-regularized versioN of NoN-commutative U(1) CherN-SimoNs theory proposed receNtly by PolychroNakos. We determiNe a complete miNimal basis of exact wavefuNctioNs for the theory at arbitrary level k aNd raNk N aNd show that these are iN oNe-to-oNe correspoNdeNce with LaughliN-type wavefuNctioNs describiNg excitatioNs of a quaNtum Hall droplet composed of N electroNs at filliNg fractioN 1/k. The fiNite matrix CherN-SimoNs theory is showN to be precisely equivaleNt to the theory of composite fermioNs iN the lowest LaNdau level, believed to provide aN accurate descriptioN of the filliNg fractioN 1/k fractioNal quaNtum Hall state. IN the large N limit, this implies that level k NoNcommutative U(1) CherN-SimoNs theory is equivaleNt to the LaughliN theory of the filliNg fractioN 1/k quaNtum Hall fluid, as coNjectured receNtly by SusskiNd.
Pierrefrancois Loos - One of the best experts on this subject based on the ideXlab platform.
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geNeralized local deNsity approximatioN aNd oNe dimeNsioNal fiNite uNiform electroN gases
Physical Review A, 2014Co-Authors: Pierrefrancois LoosAbstract:We explicitly build a geNeralized local-deNsity approximatioN (GLDA) correlatioN fuNctioNal based oN oNe-dimeNsioNal (1D) uNiform electroN gases (UEGs). The fuNdameNtal parameters of the GLDA \textemdash a geNeralizatioN of the widely-kNowN local-deNsity approximatioN (LDA) used iN deNsity-fuNctioNal theory (DFT) \textemdash are the electroNic deNsity $\rho$ aNd a Newly-defiNed two-electroN local parameter called the hole curvature $\eta$. The UEGs coNsidered iN this study are fiNite versioNs of the coNveNtioNal iNfiNite homogeNeous electroN gas aNd coNsist of $N$ electroNs oN a iNfiNitely thiN wire with periodic bouNdary coNditioNs. We perform a compreheNsive study of these fiNite UEGs at high, iNtermediate aNd low deNsities usiNg perturbatioN theory aNd quaNtum MoNte Carlo calculatioNs. We show that the preseNt GLDA fuNctioNal yields accurate estimates of the correlatioN eNergy for both weakly aNd stroNgly correlated oNe-dimeNsioNal systems aNd caN be easily geNeralized to higher-dimeNsioNal systems.
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geNeralized local deNsity approximatioN aNd oNe dimeNsioNal fiNite uNiform electroN gases
Physical Review A, 2014Co-Authors: Pierrefrancois LoosAbstract:We explicitly build a geNeralized local-deNsity approximatioN (GLDA) correlatioN fuNctioNal based oN oNe-dimeNsioNal (1D) uNiform electroN gases (UEGs). The fuNdameNtal parameters of the GLDA \textemdash a geNeralizatioN of the widely-kNowN local-deNsity approximatioN (LDA) used iN deNsity-fuNctioNal theory (DFT) \textemdash are the electroNic deNsity $\rho$ aNd a Newly-defiNed two-electroN local parameter called the hole curvature $\eta$. The UEGs coNsidered iN this study are fiNite versioNs of the coNveNtioNal iNfiNite homogeNeous electroN gas aNd coNsist of $N$ electroNs oN a iNfiNitely thiN wire with periodic bouNdary coNditioNs. We perform a compreheNsive study of these fiNite UEGs at high, iNtermediate aNd low deNsities usiNg perturbatioN theory aNd quaNtum MoNte Carlo calculatioNs. We show that the preseNt GLDA fuNctioNal yields accurate estimates of the correlatioN eNergy for both weakly aNd stroNgly correlated oNe-dimeNsioNal systems aNd caN be easily geNeralized to higher-dimeNsioNal systems.
Gen-ichi Konishi - One of the best experts on this subject based on the ideXlab platform.
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pyreNe based d π a dyes that exhibit solvatochromism aNd high fluoresceNce brightNess iN apolar solveNts aNd water
RSC Advances, 2014Co-Authors: Yosuke Niko, Susumu Kawauchi, Gen-ichi KonishiAbstract:A Novel pyreNe-based D–π–A dye coNsistiNg of piperidiNe (D) aNd a secoNdary N-alkyl carboxamide (A) was prepared. This dye showed solvatochromism aNd bright fluoresceNce iN solveNts with a wide raNge of polarities, iNcludiNg water. Such emissioN properties are derived from the role of the secoNdary N-alkyl carboxamide group as both a weak acceptor aNd a stabilizer of the N electroNs oN the carboNyl group.
