scholarly journals Local-field Effects in the High-q-vector Dielectric Response of Si

1993 ◽  
Vol 46 (5) ◽  
pp. 635 ◽  
Author(s):  
TW Josefsson ◽  
AE Smith
Keyword(s):  
Local Field ◽  
Local Fields ◽  
Brillouin Zone Boundary ◽  
High Q ◽  
Field Effects ◽  
Pseudopotential Calculations ◽  
Calculated Volume ◽  
Q Vector ◽  
Dielectric Loss Function ◽  
Volume Plasmon

The influence of microscopic or local fields on the full frequency- and wavevector-dependent dielectric loss function of Si has been calculated, based on accurate empirical pseudopotential calculations of the electronic structure. It is shown that local-field effects, dramatically significant at optical (q ~ 0) wavevectors, diminish with increasing magnitude of q to negligible proportions as q approaches the Brillouin zone boundary. In addition it is shown that the calculated volume-plasmon dispersion relation is improved in comparison with experimental results by the inclusion of local-field effects.

The Role of Local Fields in the Optical Properties of Silicon Nanocrystals

2006 ◽  
Vol 958 ◽  
Author(s):  
Fabio Trani ◽  
Domenico Ninno ◽  
Giovanni Cantele ◽  
Giuseppe Iadonisi
Keyword(s):  
Optical Properties ◽  
Local Field ◽  
Silicon Nanocrystals ◽  
Tight Binding ◽  
Visible Spectral Range ◽  
Local Fields ◽  
Strong Suppression ◽  
Field Effects ◽  
Dielectric Model

ABSTRACTIn this paper we discuss the role of local fields in the optical properties of silicon nanocrystals. Using a semiempirical tight binding approach, local field effects are included into the linear response theory, going beyond the standard independent particle approximation. The results show that local field effects give an important contribution to the optical properties of silicon nanocrystals, leading to a strong suppression of the absorption in the visible spectral range. This effect is attributed to the classical surface polarization contribution. A comparison between the atomistic tight binding approach and a classical dielectric model shows that the dielectric model gives reasonable results not only for large, but even for small silicon nanocrystals.

scholarly journals Smooth representations of unit groups of split basic algebras over non-Archimedean local fields

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Carlos A. M. André ◽  
João Dias
Keyword(s):  
Local Field ◽  
Unit Group ◽  
Basic Algebra ◽  
Local Fields ◽  
Dimensional Representation ◽  
Smooth Representation ◽  
One Dimensional ◽  
Finite Dimensional

Abstract We consider smooth representations of the unit group G = A × G=\mathcal{A}^{\times} of a finite-dimensional split basic algebra 𝒜 over a non-Archimedean local field. In particular, we prove a version of Gutkin’s conjecture, namely, we prove that every irreducible smooth representation of 𝐺 is compactly induced by a one-dimensional representation of the unit group of some subalgebra of 𝒜. We also discuss admissibility and unitarisability of smooth representations of 𝐺.

scholarly journals Generation of multiple plasmons in strontium niobates mediated by local field effects

2018 ◽  
Vol 98 (23) ◽  
Author(s):  
Tao Zhu ◽  
Paolo E. Trevisanutto ◽  
Teguh Citra Asmara ◽  
Lei Xu ◽  
Yuan Ping Feng ◽  
...  
Keyword(s):  
Local Field ◽  
Field Effects

Super-radiance from a thin solid film of three-level atoms: local-field effects

2000 ◽  
Vol 180 (1-3) ◽  
pp. 59-68 ◽  
Author(s):  
V.A. Malyshev ◽  
I.V. Ryzhov ◽  
E.D. Trifonov ◽  
A.I. Zaitsev
Keyword(s):  
Local Field ◽  
Thin Solid Film ◽  
Field Effects ◽  
Solid Film

Excitation spectra of cubic perovskite titanates

2021 ◽  
Vol 32 ◽  
Author(s):  
Hieu Nguyen-Truong
Keyword(s):  
Density Functional Theory ◽  
Local Field ◽  
Density Functional ◽  
Theoretical Calculations ◽  
Plasmon Mode ◽  
Time Dependent ◽  
Excitation Spectra ◽  
Functional Theory ◽  
Field Effects ◽  
Dependent Density

We calculate excitation spectra of cubic perovskites ATiO3 (A = Ca, Sr, Ba, Pb). The calculations are performed within the time-dependent density functional theory, including local field effects. The theoretical calculations show that the perovskites have a plasmon mode at around 12 eV, which is not observed in experiments.

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