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Título:
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Nonlocal exchange effects on the bulk plasmon dispersion relation
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Autor/a:
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João da Providência, Jr.; Barberán Falcón, Núria
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Otros autores:
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Universitat de Barcelona |
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Abstract:
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Starting from the action principle, a bulk plasmon dispersion relation is obtained. We work with Slater determinants built of plane waves and consider a Hermitian generator of plasma oscillations (with well-defined q momentum) S=αQ-βP, where Q=
tsum
j
cos(q⋅
x
j
) is a time-even Hermitian generator, P=scrB
tsum
j
[
p
j
⋅q sin(q⋅
x
j
)+sin(q⋅
x
j
)
p
j
⋅q] is a time-odd Hermitian generator, α(t) and β(t) are real time-dependent functions, and scrB is a real normalization constant. If the parameters α and β are small, the amplitude of the plasma oscillations generated by S is small. The quantum-mechanical action principle leads, in the harmonic approximation, to a quadratic Lagrangian
L
(
2
)
(α,β) from which the dispersion relation is obtained. The nonlocal expression of the exchange contribution is explicitly obtained. The resulting bulk plasmon dispersion relation is related to the energy-weighted and cubic-energy-weighted sum rules. Finally, we compare our results with the experimental data. |
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Materia(s):
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-Plasmons (Física)
-Relacions de dispersió
-Plasmons (Physics)
-Dispersion relations |
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Derechos:
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(c) The American Physical Society, 1992
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Tipo de documento:
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Artículo
Artículo - Versión publicada |
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Editor:
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The American Physical Society
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Compartir:
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