Response function and plasmon dispersion for strongly coupled Coulomb liquids

Kalman, G.; Golden, Kenneth I.

doi:10.1103/physreva.41.5516

Cited by 150 publications

(122 citation statements)

References 48 publications

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“…These results were already anticipated in [11,12]. Note that the gap frequencies are ordered as ω + > ω T > ω − .…”

supporting

confidence: 68%

“…However, the first systematic and reliable analysis of this problem, primarily through molecular dynamics (MD) computer simulation was done by Hansen and collaborators [7,8]; in particular Hansen [8] verified the change of the BG behavior to a negative dispersion, the hallmark phenomenon of strong coupling, which was predicted and investigated by a number of workers [9,10] around the same time. A different theoretical approach, the Quasilocalized Charge Approximation (QLCA), geared for the study of strongly coupled Coulomb systems was introduced by Kalman and Golden [11,12] and combined with advanced MD computer simulations has led to a thorough investigation of the plasmon dispersion. Experimentally, the plasmon dispersion of the electron gas has been mapped directly and indirectly in various condensed matter situations at low or moderate coupling values; with the advent of complex (dusty) plasma experiments, the way to directly observing strongly coupled plasmon behavior in the laboratory has opened up.…”

mentioning

confidence: 99%

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Second plasmon and collective modes in binary Coulomb systems

Kalman¹,

Hartmann²,

Golden³

2014

EPL

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In a system consisting of two different charged species we identify the excitation of a second, low frequency plasmon. At strong coupling the doublet of high frequency (first) and low frequency (second) plasmons replaces the single plasmon excitation that prevails at weak coupling. We observe the formation of the second plasmon from the acoustic Goldstone type mode associated with short range interaction as the range is extended to infinity. The existence of plasmons in many body systems interacting through a Coulomb potential (plasmas, electron gases, etc.) with a characteristic oscillation frequency, the plasma frequency(with the symbols having their usual meaning) has been known for a long time [1]. The identification of this phenomenon as a collective excitation -in fact, the very introduction of the idea of collective excitations and the notion of collective coordinates -is due to the pioneering series of works by Bohm, Gross and Pines [2][3][4]. It was also Bohm and Gross [2] (BG) who determined the eponymous k-dependent positive dispersion of the plasmon, caused by the random motion of the particles. Soon, however, it became clear that the BG dispersion and the underlying theoretical approach (which later was reformulated in many differ guises [3,5] and has commonly become known as the Random Phase Approximation (RPA)) are appropriate for weak coupling only. The coupling strength is conveniently defined as the ratio of the potential energy of the particles to their kinetic energy. The appropriate parameters that characterize the coupling strength for classical systems are Γ = Z 2 e 2 /ak B T and for quantum systems r s = a/a B (a is the Wigner-Seitz radius, a B the Bohr radius and T the temperature). Motivated by the case of the electron gas in metals where the condition r s < 1 is mildly violated, it was Singwi and collaborators [6] who have made the first serious attempts to study the effect of strong coupling on the properties of the plasmon. However, the first systematic and reliable analysis of this problem, primarily through molecular dynamics (MD) computer simulation was done by Hansen and collaborators [7,8]; in particular Hansen [8] verified the change of the BG behavior to a negative dispersion, the hallmark phenomenon of strong coupling, which was predicted and investigated by a number of workers [9,10] around the same time. A different theoretical approach, the Quasilocalized Charge Approximation (QLCA), geared for the study of strongly coupled Coulomb systems was introduced by Kalman and Golden [11,12] and combined with advanced MD computer simulations has led to a thorough investigation of the plasmon dispersion. Experimentally, the plasmon dispersion of the electron gas has been mapped directly and indirectly in various condensed matter situations at low or moderate coupling values; with the advent of complex (dusty) plasma experiments, the way to directly observing strongly coupled plasmon behavior in the laboratory has opened up.Looking at the problem from a more general point of view, w...

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“…These results were already anticipated in [11,12]. Note that the gap frequencies are ordered as ω + > ω T > ω − .…”

supporting

confidence: 68%

mentioning

confidence: 99%

Second plasmon and collective modes in binary Coulomb systems

Kalman¹,

Hartmann²,

Golden³

2014

EPL

Self Cite

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“…In order to establish the connection to the ground state exact relations 47 of exchange correlation energy, ε xc , we see from (40) …”

Section: B Connection To Density Functionalsmentioning

confidence: 99%

“…We restrict here to a one component system though the generalization to multicomponent systems is straight forward 37,38 and considered in different approaches [39][40][41] .…”

Section: Introductionmentioning

confidence: 99%

Dynamical local field, compressibility, and frequency sum rules for quasiparticles

Morawetz

2002

Phys. Rev. B

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The finite temperature dynamical response function including the dynamical local field is derived within a quasiparticle picture for interacting one-, two-and three dimensional Fermi systems. The correlations are assumed to be given by a density dependent effective mass, quasiparticle energy shift and relaxation time. The latter one describes disorder or collisional effects. This parameterization of correlations includes local density functionals as a special case and is therefore applicable for density functional theories. With a single static local field, the third order frequency sum rule can be fulfilled simultaneously with the compressibility sum rule by relating the effective mass and quasiparticle energy shift to the structure function or pair correlation function. Consequently, solely local density functionals without taking into account effective masses cannot fulfill both sum rules simultaneously with a static local field. The comparison to the Monte-Carlo data seems to support such quasiparticle picture. 05.30.Fk,21.60.Ev, 24.30.Cz, 24.60.Ky

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“…If one puts Q( k, ω) = 0 one obtains the expression of the inverse dielectric function obtained within the quasilocalized charge approach of Kalman [23]. The disadvantage of this choice of Q is that damping is not taken into account.…”

Section: Analysis Of the Resultsmentioning

confidence: 99%