Merge branch 'article_wrk' into article
Former-commit-id: 91ffb5d42066adae1d3193b9c5125f2d546d3314
This commit is contained in:
commit
7573c2987b
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@ -491,21 +491,12 @@ These are compatibility macros for the (...)-old files:
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\end_layout
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\end_layout
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||||||
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||||||
\begin_layout Title
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\begin_layout Title
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||||||
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Many-particle
|
||||||
\begin_inset Formula $T$
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\begin_inset Formula $T$
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||||||
\end_inset
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\end_inset
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||||||
|
|
||||||
-matrix simulations in finite and infinite systems of electromagnetic scatterers
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-matrix simulations for nanophotonics: symmetries, scattering and lattice
|
||||||
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modes
|
||||||
\begin_inset Marginal
|
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||||||
status open
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||||||
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||||||
\begin_layout Plain Layout
|
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||||||
(TODO better title)
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\end_layout
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||||||
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||||||
\end_inset
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||||||
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||||||
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||||||
\end_layout
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\end_layout
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||||||
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||||||
\begin_layout Standard
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\begin_layout Standard
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||||||
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@ -521,7 +512,7 @@ Multiple-scattering
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\end_layout
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\end_layout
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||||||
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||||||
\begin_layout Itemize
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\begin_layout Itemize
|
||||||
Multiple-scattering
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Many-particle
|
||||||
\begin_inset Formula $T$
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\begin_inset Formula $T$
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||||||
\end_inset
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\end_inset
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||||||
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@ -529,6 +520,13 @@ Multiple-scattering
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modes.
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modes.
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\end_layout
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\end_layout
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||||||
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||||||
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\begin_layout Itemize
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||||||
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\begin_inset Formula $T$
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||||||
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\end_inset
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||||||
|
|
||||||
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-matrix simulations in finite and infinite systems of electromagnetic scatterers
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||||||
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\end_layout
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||||||
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||||||
\begin_layout Standard
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\begin_layout Standard
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||||||
\begin_inset Note Note
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\begin_inset Note Note
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||||||
status open
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status open
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||||||
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@ -617,8 +615,13 @@ The T-matrix multiple scattering method (TMMSM) can be used to solve the
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||||||
\begin_layout Abstract
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\begin_layout Abstract
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||||||
Here we extend the method to infinite periodic structures using Ewald-type
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Here we extend the method to infinite periodic structures using Ewald-type
|
||||||
lattice summation, and we exploit the possible symmetries of the structure
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lattice summation, and we exploit the possible symmetries of the structure
|
||||||
to further improve its efficiency.
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to further improve its efficiency, so that systems containing tens of thousands
|
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of particles can be studied with relative ease.
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||||||
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\begin_inset Note Note
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||||||
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status open
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||||||
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||||||
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\begin_layout Plain Layout
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||||||
\begin_inset Marginal
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\begin_inset Marginal
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||||||
status open
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status open
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||||||
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||||||
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@ -629,6 +632,11 @@ Should I mention also the cross sections formulae in abstract / intro?
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\end_inset
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\end_inset
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||||||
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||||||
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\end_layout
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\end_inset
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\end_layout
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\end_layout
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||||||
\begin_layout Abstract
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\begin_layout Abstract
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@ -794,6 +802,10 @@ Maybe put the numerical results separately in the end.
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\end_layout
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\end_layout
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||||||
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||||||
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\begin_layout Section*
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\begin_inset Note Note
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||||||
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status open
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\begin_layout Section*
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\begin_layout Section*
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||||||
TODO
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TODO
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\end_layout
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\end_layout
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||||||
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@ -821,6 +833,12 @@ Truncation notation.
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Example results and benchmarks with BEM; figures!
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Example results and benchmarks with BEM; figures!
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||||||
\end_layout
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\end_layout
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||||||
|
|
||||||
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\begin_deeper
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||||||
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\begin_layout Itemize
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||||||
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Given up for BEM, SCUFF-EM too unreliable.
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\end_layout
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||||||
|
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||||||
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\end_deeper
|
||||||
\begin_layout Itemize
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\begin_layout Itemize
|
||||||
Carefully check the transformation directions in sec.
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Carefully check the transformation directions in sec.
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||||||
|
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||||||
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@ -841,7 +859,18 @@ Check whether everything written is correct also for non-symmorphic space
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groups.
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groups.
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\end_layout
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\end_layout
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||||||
|
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||||||
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\begin_deeper
|
||||||
\begin_layout Itemize
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\begin_layout Itemize
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Given up
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\end_layout
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\end_deeper
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\end_inset
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\end_layout
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||||||
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||||||
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\begin_layout Standard
|
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\begin_inset Note Note
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\begin_inset Note Note
|
||||||
status open
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status open
|
||||||
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||||||
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@ -105,8 +105,17 @@ name "sec:Applications"
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\end_layout
|
\end_layout
|
||||||
|
|
||||||
\begin_layout Standard
|
\begin_layout Standard
|
||||||
Finally, we present some results obtained with the QPMS suite as well as
|
Finally, we present some results obtained with the QPMS suite
|
||||||
benchmarks with BEM.
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\begin_inset Note Note
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||||||
|
status open
|
||||||
|
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||||||
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\begin_layout Plain Layout
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||||||
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as well as benchmarks with BEM
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||||||
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\end_layout
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||||||
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||||||
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\end_inset
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||||||
|
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||||||
|
.
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||||||
Scripts to reproduce these results are available under the
|
Scripts to reproduce these results are available under the
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||||||
\family typewriter
|
\family typewriter
|
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examples
|
examples
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||||||
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@ -115,20 +124,16 @@ examples
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\end_layout
|
\end_layout
|
||||||
|
|
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\begin_layout Subsection
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\begin_layout Subsection
|
||||||
Response of a rectangular nanoplasmonic array
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Optical response of a square array; finite size effects
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||||||
\end_layout
|
\end_layout
|
||||||
|
|
||||||
\begin_layout Standard
|
\begin_layout Standard
|
||||||
Our first example deals with a plasmonic array made of golden nanoparticles
|
Our first example deals with a plasmonic array made of silver nanoparticles
|
||||||
placed in a rectangular planar configuration.
|
placed in a square planar configuration.
|
||||||
The nanoparticles have shape of right circular cylinder with radius 50
|
The nanoparticles have shape of right circular cylinder with 30 nm radius
|
||||||
nm and height 50 nm.
|
and 30 nm in height.
|
||||||
The particles are placed with periodicities
|
The particles are placed with periodicity
|
||||||
\begin_inset Formula $p_{x}=\SI{621}{nm}$
|
\begin_inset Formula $p_{x}=p_{y}=375\,\mathrm{nm}$
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||||||
\end_inset
|
|
||||||
|
|
||||||
,
|
|
||||||
\begin_inset Formula $p_{y}=\SI{571}{nm}$
|
|
||||||
\end_inset
|
\end_inset
|
||||||
|
|
||||||
into an isotropic medium with a constant refraction index
|
into an isotropic medium with a constant refraction index
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||||||
|
@ -136,7 +141,30 @@ Our first example deals with a plasmonic array made of golden nanoparticles
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||||||
\end_inset
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\end_inset
|
||||||
|
|
||||||
.
|
.
|
||||||
For gold, we use the optical properties listed in
|
For silver, we use Drude-Lorentz model with parameters from
|
||||||
|
\begin_inset CommandInset citation
|
||||||
|
LatexCommand cite
|
||||||
|
key "rakic_optical_1998"
|
||||||
|
literal "false"
|
||||||
|
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
, and the
|
||||||
|
\begin_inset Formula $T$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
-matrix of a single particle we compute using the null-field method (with
|
||||||
|
cutoff
|
||||||
|
\begin_inset Formula $l_{\mathrm{max}}=6$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
for solving the null-field equations).
|
||||||
|
|
||||||
|
\begin_inset Note Note
|
||||||
|
status collapsed
|
||||||
|
|
||||||
|
\begin_layout Plain Layout
|
||||||
|
the optical properties listed in
|
||||||
\begin_inset CommandInset citation
|
\begin_inset CommandInset citation
|
||||||
LatexCommand cite
|
LatexCommand cite
|
||||||
key "johnson_optical_1972"
|
key "johnson_optical_1972"
|
||||||
|
@ -145,7 +173,16 @@ literal "false"
|
||||||
\end_inset
|
\end_inset
|
||||||
|
|
||||||
interpolated with cubical splines.
|
interpolated with cubical splines.
|
||||||
The particles' cylindrical shape is approximated with a triangular mesh
|
\end_layout
|
||||||
|
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
|
||||||
|
\begin_inset Note Note
|
||||||
|
status open
|
||||||
|
|
||||||
|
\begin_layout Plain Layout
|
||||||
|
The particles' cylindrical shape is approximated with a triangular mesh
|
||||||
with XXX boundary elements.
|
with XXX boundary elements.
|
||||||
\begin_inset Marginal
|
\begin_inset Marginal
|
||||||
status open
|
status open
|
||||||
|
@ -157,42 +194,94 @@ Show the mesh as well?
|
||||||
\end_inset
|
\end_inset
|
||||||
|
|
||||||
|
|
||||||
|
\end_layout
|
||||||
|
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
|
||||||
\end_layout
|
\end_layout
|
||||||
|
|
||||||
\begin_layout Standard
|
\begin_layout Standard
|
||||||
We consider finite arrays with
|
We consider finite arrays with
|
||||||
\begin_inset Formula $N_{x}\times N_{y}=\ldots\times\ldots,\ldots\times\ldots,\ldots\times\ldots$
|
\begin_inset Formula $N_{x}\times N_{y}=40\times40,70\times70,100\times100$
|
||||||
\end_inset
|
\end_inset
|
||||||
|
|
||||||
particles and also the corresponding infinite array, and simulate their
|
particles and also the corresponding infinite array, and simulate their
|
||||||
absorption when irradiated by circularly polarised plane waves with energies
|
absorption when irradiated by
|
||||||
from xx to yy and incidence direction lying in the
|
\begin_inset Note Note
|
||||||
|
status open
|
||||||
|
|
||||||
|
\begin_layout Plain Layout
|
||||||
|
circularly
|
||||||
|
\end_layout
|
||||||
|
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
plane waves with incidence direction lying in the
|
||||||
\begin_inset Formula $xz$
|
\begin_inset Formula $xz$
|
||||||
\end_inset
|
\end_inset
|
||||||
|
|
||||||
plane.
|
plane.
|
||||||
The results are shown in Figure
|
We concentrate on the behaviour around the first diffracted order crossing
|
||||||
|
at the
|
||||||
|
\begin_inset Formula $\Gamma$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
point, which happens around frequency
|
||||||
|
\begin_inset Formula $2.18\,\mathrm{eV}/\hbar$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
.
|
||||||
|
Figure
|
||||||
\begin_inset CommandInset ref
|
\begin_inset CommandInset ref
|
||||||
LatexCommand ref
|
LatexCommand ref
|
||||||
reference "fig:Example rectangular absorption"
|
reference "fig:Example rectangular absorption infinite"
|
||||||
plural "false"
|
plural "false"
|
||||||
caps "false"
|
caps "false"
|
||||||
noprefix "false"
|
noprefix "false"
|
||||||
|
|
||||||
\end_inset
|
\end_inset
|
||||||
|
|
||||||
.
|
shows the response for the infinite array for a range of frequencies; here
|
||||||
|
in particular we used the multipole cutoff
|
||||||
\begin_inset Marginal
|
\begin_inset Formula $l_{\mathrm{max}}=3$
|
||||||
status open
|
\end_inset
|
||||||
|
|
||||||
\begin_layout Plain Layout
|
for the interparticle interactions, although there is no visible difference
|
||||||
Mention lMax.
|
if we use
|
||||||
\end_layout
|
\begin_inset Formula $l_{\mathrm{max}}=2$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
instead due to the small size of the particles.
|
||||||
|
In Figure
|
||||||
|
\begin_inset CommandInset ref
|
||||||
|
LatexCommand ref
|
||||||
|
reference "fig:Example rectangular absorption size comparison"
|
||||||
|
plural "false"
|
||||||
|
caps "false"
|
||||||
|
noprefix "false"
|
||||||
|
|
||||||
\end_inset
|
\end_inset
|
||||||
|
|
||||||
|
, we compare the response of differently sized array slightly below the
|
||||||
|
diffracted order crossing.
|
||||||
|
We see that far from the diffracted orders, all the cross sections are
|
||||||
|
almost directly proportional to the total number of particles.
|
||||||
|
However, near the resonances, the size effects become apparent: the lattice
|
||||||
|
resonances tend to fade away as the size of the array decreases.
|
||||||
|
Moreover, the proportion between the absorbed and scattered parts changes
|
||||||
|
as while the small arrays tend to more just scatter the incident light
|
||||||
|
into different directions, in larger arrays, it is more
|
||||||
|
\begin_inset Quotes eld
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
likely
|
||||||
|
\begin_inset Quotes erd
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
that the light will scatter many times, each time sacrifying a part of
|
||||||
|
its energy to the ohmic losses.
|
||||||
|
|
||||||
\begin_inset Float figure
|
\begin_inset Float figure
|
||||||
placement document
|
placement document
|
||||||
alignment document
|
alignment document
|
||||||
|
@ -201,37 +290,49 @@ sideways false
|
||||||
status open
|
status open
|
||||||
|
|
||||||
\begin_layout Plain Layout
|
\begin_layout Plain Layout
|
||||||
|
\align center
|
||||||
|
\begin_inset Graphics
|
||||||
|
filename figs/inf.pdf
|
||||||
|
width 45text%
|
||||||
|
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
|
||||||
|
\begin_inset Graphics
|
||||||
|
filename figs/inf_big_px.pdf
|
||||||
|
width 45text%
|
||||||
|
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
|
||||||
\begin_inset Caption Standard
|
\begin_inset Caption Standard
|
||||||
|
|
||||||
\begin_layout Plain Layout
|
\begin_layout Plain Layout
|
||||||
Absorption of rectangular arrays of golden nanoparticles with periodicities
|
Response of an infinite square array of silver nanoparticles with periodicities
|
||||||
|
|
||||||
\begin_inset Formula $p_{x}=\SI{621}{nm}$
|
\begin_inset Formula $p_{x}=p_{y}=375\,\mathrm{nm}$
|
||||||
\end_inset
|
\end_inset
|
||||||
|
|
||||||
,
|
to plane waves incident in the
|
||||||
\begin_inset Formula $p_{y}=\SI{571}{nm}$
|
\begin_inset Formula $xz$
|
||||||
\end_inset
|
\end_inset
|
||||||
|
|
||||||
with a)
|
-plane.
|
||||||
\begin_inset Formula $\ldots\times\ldots$
|
Left:
|
||||||
|
\begin_inset Formula $y$
|
||||||
\end_inset
|
\end_inset
|
||||||
|
|
||||||
, b)
|
-polarised waves, right:
|
||||||
\begin_inset Formula $\ldots\times\ldots$
|
\begin_inset Formula $x$
|
||||||
\end_inset
|
\end_inset
|
||||||
|
|
||||||
, c)
|
-polarised waves.
|
||||||
\begin_inset Formula $\ldots\times\ldots$
|
The images show extinction, scattering and absorption cross section per
|
||||||
\end_inset
|
unit cell.
|
||||||
|
|
||||||
and d) infinitely many particles, irradiated by circularly polarised plane
|
|
||||||
waves.
|
|
||||||
e) Absoption profile of a single nanoparticle.
|
|
||||||
|
|
||||||
\begin_inset CommandInset label
|
\begin_inset CommandInset label
|
||||||
LatexCommand label
|
LatexCommand label
|
||||||
name "fig:Example rectangular absorption"
|
name "fig:Example rectangular absorption infinite"
|
||||||
|
|
||||||
\end_inset
|
\end_inset
|
||||||
|
|
||||||
|
@ -245,19 +346,114 @@ name "fig:Example rectangular absorption"
|
||||||
|
|
||||||
\end_inset
|
\end_inset
|
||||||
|
|
||||||
We compared the
|
|
||||||
\begin_inset Formula $\ldots\times\ldots$
|
|
||||||
\end_inset
|
|
||||||
|
|
||||||
case with a purely BEM-based solution obtained using the
|
|
||||||
\family typewriter
|
|
||||||
scuff-scatter
|
|
||||||
\family default
|
|
||||||
utility.
|
|
||||||
TODO WHAT DO WE GET?
|
|
||||||
\end_layout
|
\end_layout
|
||||||
|
|
||||||
\begin_layout Standard
|
\begin_layout Standard
|
||||||
|
\begin_inset Float figure
|
||||||
|
placement document
|
||||||
|
alignment document
|
||||||
|
wide false
|
||||||
|
sideways false
|
||||||
|
status open
|
||||||
|
|
||||||
|
\begin_layout Plain Layout
|
||||||
|
|
||||||
|
\end_layout
|
||||||
|
|
||||||
|
\begin_layout Plain Layout
|
||||||
|
\align center
|
||||||
|
\begin_inset Graphics
|
||||||
|
filename figs/sqlat_scattering_cuts.pdf
|
||||||
|
width 90col%
|
||||||
|
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
|
||||||
|
\end_layout
|
||||||
|
|
||||||
|
\begin_layout Plain Layout
|
||||||
|
\begin_inset Caption Standard
|
||||||
|
|
||||||
|
\begin_layout Plain Layout
|
||||||
|
Comparison of optical responses of differently sized square arrays of silver
|
||||||
|
nanoparticles with the same periodicity
|
||||||
|
\begin_inset Formula $p_{x}=p_{y}=375\,\mathrm{nm}$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
.
|
||||||
|
In all cases, the array is illuminated by plane waves linearly polarised
|
||||||
|
in the
|
||||||
|
\begin_inset Formula $y$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
-direction, with constant frequency
|
||||||
|
\begin_inset Formula $2.15\,\mathrm{eV}/\hbar$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
.
|
||||||
|
The cross sections are normalised by the total number of particles in the
|
||||||
|
array.
|
||||||
|
\begin_inset CommandInset label
|
||||||
|
LatexCommand label
|
||||||
|
name "fig:Example rectangular absorption size comparison"
|
||||||
|
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
|
||||||
|
\end_layout
|
||||||
|
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
|
||||||
|
\end_layout
|
||||||
|
|
||||||
|
\begin_layout Plain Layout
|
||||||
|
|
||||||
|
\end_layout
|
||||||
|
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
|
||||||
|
\end_layout
|
||||||
|
|
||||||
|
\begin_layout Standard
|
||||||
|
The finite-size cases in Figure
|
||||||
|
\begin_inset CommandInset ref
|
||||||
|
LatexCommand ref
|
||||||
|
reference "fig:Example rectangular absorption size comparison"
|
||||||
|
plural "false"
|
||||||
|
caps "false"
|
||||||
|
noprefix "false"
|
||||||
|
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
were computed with quadrupole truncation
|
||||||
|
\begin_inset Formula $l\le2$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
and using the decomposition into the eight irreducible representations
|
||||||
|
of group
|
||||||
|
\begin_inset Formula $D_{2h}$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
.
|
||||||
|
The
|
||||||
|
\begin_inset Formula $100\times100$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
array took about 4 h to compute on Dell PowerEdge C4130 with 12 core Xeon
|
||||||
|
E5 2680 v3 2.50GHz, requiring about 20 GB of RAM.
|
||||||
|
For smaller systems, the computation time decreases quickly, as the main
|
||||||
|
bottleneck is the LU factorisation.
|
||||||
|
In any case, there is still room for optimisation in the QPMS suite.
|
||||||
|
\end_layout
|
||||||
|
|
||||||
|
\begin_layout Standard
|
||||||
|
\begin_inset Note Note
|
||||||
|
status open
|
||||||
|
|
||||||
|
\begin_layout Plain Layout
|
||||||
In the infinite case, we benchmarked against a pseudorandom selection of
|
In the infinite case, we benchmarked against a pseudorandom selection of
|
||||||
|
|
||||||
\begin_inset Formula $\left(\vect k,\omega\right)$
|
\begin_inset Formula $\left(\vect k,\omega\right)$
|
||||||
|
@ -283,17 +479,283 @@ TODO also details about the machines used.
|
||||||
\end_inset
|
\end_inset
|
||||||
|
|
||||||
|
|
||||||
|
\end_layout
|
||||||
|
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
|
||||||
\end_layout
|
\end_layout
|
||||||
|
|
||||||
\begin_layout Subsection
|
\begin_layout Subsection
|
||||||
Modes of a rectangular nanoplasmonic array
|
Lattice mode structure
|
||||||
|
\end_layout
|
||||||
|
|
||||||
|
\begin_layout Subsection
|
||||||
|
Square lattice
|
||||||
\end_layout
|
\end_layout
|
||||||
|
|
||||||
\begin_layout Standard
|
\begin_layout Standard
|
||||||
Next, we study the eigenmode problem of the same rectangular arrays.
|
Next, we study the lattice mode problem of the same square arrays.
|
||||||
The system is lossy, therefore the eigenfrequencies are complex and we
|
First we consider the mode problem exactly at the
|
||||||
need to have a model of the material optical properties also for complex
|
\begin_inset Formula $\Gamma$
|
||||||
frequencies.
|
\end_inset
|
||||||
|
|
||||||
|
point,
|
||||||
|
\begin_inset Formula $\vect k=0$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
.
|
||||||
|
Before proceeding with more sophisticated methods, it is often helpful
|
||||||
|
to look at the singular values of mode problem matrix
|
||||||
|
\begin_inset Formula $M\left(\omega,\vect k\right)$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
from the lattice mode equation
|
||||||
|
\begin_inset CommandInset ref
|
||||||
|
LatexCommand eqref
|
||||||
|
reference "eq:lattice mode equation"
|
||||||
|
plural "false"
|
||||||
|
caps "false"
|
||||||
|
noprefix "false"
|
||||||
|
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
, as shown in Fig.
|
||||||
|
|
||||||
|
\begin_inset CommandInset ref
|
||||||
|
LatexCommand ref
|
||||||
|
reference "fig:square lattice real interval SVD"
|
||||||
|
plural "false"
|
||||||
|
caps "false"
|
||||||
|
noprefix "false"
|
||||||
|
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
.
|
||||||
|
This can be always done, even with tabulated/interpolated material properties
|
||||||
|
and/or
|
||||||
|
\begin_inset Formula $T$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
-matrices.
|
||||||
|
An additional insight, especially in the high-symmetry points of the Brillouin
|
||||||
|
zone, is provided by decomposition of the matrix into irreps – in this
|
||||||
|
case of group
|
||||||
|
\begin_inset Formula $D_{4h}$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
, which corresponds to the point group symmetry of the array at the
|
||||||
|
\begin_inset Formula $\Gamma$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
point.
|
||||||
|
Although on the picture none of the SVDs hits manifestly zero, we see two
|
||||||
|
prominent dips in the
|
||||||
|
\begin_inset Formula $E'$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
and
|
||||||
|
\begin_inset Formula $A_{2}''$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
irrep subspaces, which is a sign of an actual solution nearby in the complex
|
||||||
|
plane.
|
||||||
|
Moreover, there might be some less obvious minima in the very vicinity
|
||||||
|
of the diffracted order crossing which do not appear in the picture due
|
||||||
|
to rough frequency sampling.
|
||||||
|
\begin_inset Float figure
|
||||||
|
placement document
|
||||||
|
alignment document
|
||||||
|
wide false
|
||||||
|
sideways false
|
||||||
|
status open
|
||||||
|
|
||||||
|
\begin_layout Plain Layout
|
||||||
|
\align center
|
||||||
|
\begin_inset Graphics
|
||||||
|
filename figs/cyl_r30nm_h30nm_p375nmx375nm_mAg_bg1.52_φ0_θ(-0.0075_0.0075)π_ψ0.5π_χ0π_f2.11–2.23eV_L3.pdf
|
||||||
|
width 80col%
|
||||||
|
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
|
||||||
|
\end_layout
|
||||||
|
|
||||||
|
\begin_layout Plain Layout
|
||||||
|
\begin_inset Caption Standard
|
||||||
|
|
||||||
|
\begin_layout Plain Layout
|
||||||
|
Singular values of the mode problem matrix
|
||||||
|
\begin_inset Formula $\truncated{M\left(\omega,\vect k=0\right)}3$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
for a real frequency interval.
|
||||||
|
The irreducible representations of
|
||||||
|
\begin_inset Formula $D_{4h}$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
are labeled with different colors.
|
||||||
|
The density of the data points on the horizontal axis is
|
||||||
|
\begin_inset Formula $1/\mathrm{meV}$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
.
|
||||||
|
|
||||||
|
\begin_inset CommandInset label
|
||||||
|
LatexCommand label
|
||||||
|
name "fig:square lattice real interval SVD"
|
||||||
|
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
|
||||||
|
\end_layout
|
||||||
|
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
|
||||||
|
\end_layout
|
||||||
|
|
||||||
|
\begin_layout Plain Layout
|
||||||
|
|
||||||
|
\end_layout
|
||||||
|
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
|
||||||
|
\end_layout
|
||||||
|
|
||||||
|
\begin_layout Standard
|
||||||
|
As we have used only analytical ingredients in
|
||||||
|
\begin_inset Formula $M\left(\omega,\vect k\right)$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
, the matrix is itself analytical, hence Beyn's algorithm can be used to
|
||||||
|
search for complex mode frequencies, which is shown in Figure
|
||||||
|
\begin_inset CommandInset ref
|
||||||
|
LatexCommand ref
|
||||||
|
reference "fig:square lattice beyn dispersion"
|
||||||
|
plural "false"
|
||||||
|
caps "false"
|
||||||
|
noprefix "false"
|
||||||
|
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
.
|
||||||
|
The number of the frequency point found is largely dependent on the parameters
|
||||||
|
used in Beyn's algorithm, mostly the integration contour in the frequency
|
||||||
|
space.
|
||||||
|
Here we used ellipses discretised by 250 points each, with edges nearly
|
||||||
|
touching the empty lattice diffracted orders (from either above or below
|
||||||
|
in the real part), and with major axis covering 1/5 of the interval between
|
||||||
|
two diffracted orders.
|
||||||
|
At the
|
||||||
|
\begin_inset Formula $\Gamma$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
point, the algorithm finds the actual complex positions of the suspected
|
||||||
|
|
||||||
|
\begin_inset Formula $E'$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
and
|
||||||
|
\begin_inset Formula $A_{2}''$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
modes without a problem, as well as their continuations to the other nearby
|
||||||
|
values of
|
||||||
|
\begin_inset Formula $\vect k$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
.
|
||||||
|
However, for further
|
||||||
|
\begin_inset Formula $\vect k$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
it might
|
||||||
|
\begin_inset Quotes eld
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
lose track
|
||||||
|
\begin_inset Quotes erd
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
, especially as the modes cross the diffracted orders.
|
||||||
|
As a result, the parameters of Beyn's algorithm often require manual tuning
|
||||||
|
based on the observed behaviour.
|
||||||
|
|
||||||
|
\begin_inset Float figure
|
||||||
|
placement document
|
||||||
|
alignment document
|
||||||
|
wide false
|
||||||
|
sideways false
|
||||||
|
status open
|
||||||
|
|
||||||
|
\begin_layout Plain Layout
|
||||||
|
\align center
|
||||||
|
\begin_inset Graphics
|
||||||
|
filename figs/sqlat_beyn_dispersion.pdf
|
||||||
|
width 80col%
|
||||||
|
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
|
||||||
|
\end_layout
|
||||||
|
|
||||||
|
\begin_layout Plain Layout
|
||||||
|
\begin_inset Caption Standard
|
||||||
|
|
||||||
|
\begin_layout Plain Layout
|
||||||
|
Solutions of the lattice mode problem
|
||||||
|
\begin_inset Formula $\truncated{M\left(\omega,\vect k\right)}3$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
found using Beyn's method nearby the first diffracted order crossing at
|
||||||
|
the
|
||||||
|
\begin_inset Formula $\Gamma$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
point for
|
||||||
|
\begin_inset Formula $k_{y}=0$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
.
|
||||||
|
At the
|
||||||
|
\begin_inset Formula $\Gamma$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
point, they are classified according to the irreducible representations
|
||||||
|
of
|
||||||
|
\begin_inset Formula $D_{4h}$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
.
|
||||||
|
|
||||||
|
\begin_inset CommandInset label
|
||||||
|
LatexCommand label
|
||||||
|
name "fig:square lattice beyn dispersion"
|
||||||
|
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
|
||||||
|
\end_layout
|
||||||
|
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
|
||||||
|
\end_layout
|
||||||
|
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
|
||||||
|
\end_layout
|
||||||
|
|
||||||
|
\begin_layout Standard
|
||||||
|
\begin_inset Note Note
|
||||||
|
status open
|
||||||
|
|
||||||
|
\begin_layout Plain Layout
|
||||||
|
The system is lossy, therefore the eigenfrequencies are complex and we need
|
||||||
|
to have a model of the material optical properties also for complex frequencies.
|
||||||
So in this case we use the Drude-Lorentz model for gold with parameters
|
So in this case we use the Drude-Lorentz model for gold with parameters
|
||||||
as in
|
as in
|
||||||
\begin_inset CommandInset citation
|
\begin_inset CommandInset citation
|
||||||
|
@ -306,6 +768,11 @@ literal "false"
|
||||||
.
|
.
|
||||||
\end_layout
|
\end_layout
|
||||||
|
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
|
||||||
|
\end_layout
|
||||||
|
|
||||||
\begin_layout Subsubsection
|
\begin_layout Subsubsection
|
||||||
Effects of multipole cutoff
|
Effects of multipole cutoff
|
||||||
\end_layout
|
\end_layout
|
||||||
|
|
|
@ -379,7 +379,13 @@ noprefix "false"
|
||||||
|
|
||||||
describes the
|
describes the
|
||||||
\emph on
|
\emph on
|
||||||
lattice modes.
|
lattice modes
|
||||||
|
\emph default
|
||||||
|
, i.e.
|
||||||
|
electromagnetic excitations that can sustain themselves for prolonged time
|
||||||
|
even without external driving
|
||||||
|
\emph on
|
||||||
|
.
|
||||||
|
|
||||||
\emph default
|
\emph default
|
||||||
Non-trivial solutions to
|
Non-trivial solutions to
|
||||||
|
@ -1724,7 +1730,32 @@ One pecularity of the two-dimensional case is the two-branchedness of the
|
||||||
\begin_inset Formula $\Gamma\left(\frac{1}{2}-j,z\right)$
|
\begin_inset Formula $\Gamma\left(\frac{1}{2}-j,z\right)$
|
||||||
\end_inset
|
\end_inset
|
||||||
|
|
||||||
appearing in the long-range part.
|
appearing in the long-range part (in the cases
|
||||||
|
\begin_inset Formula $d=1,3$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
the function
|
||||||
|
\begin_inset Formula $\gamma\left(z\right)$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
appears with even powers, and
|
||||||
|
\begin_inset Formula $\Gamma\left(-j,z\right)$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
is meromorphic for integer
|
||||||
|
\begin_inset Formula $j$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
|
||||||
|
\begin_inset CommandInset citation
|
||||||
|
LatexCommand cite
|
||||||
|
after "8.2.9"
|
||||||
|
key "NIST:DLMF"
|
||||||
|
literal "false"
|
||||||
|
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
).
|
||||||
As a consequence, if we now explicitly label the dependence on the wavenumber,
|
As a consequence, if we now explicitly label the dependence on the wavenumber,
|
||||||
|
|
||||||
\begin_inset Formula $\sigma_{l,m}^{\left(\mathrm{L},\eta\right)}\left(\kappa,\vect k,\vect s\right)$
|
\begin_inset Formula $\sigma_{l,m}^{\left(\mathrm{L},\eta\right)}\left(\kappa,\vect k,\vect s\right)$
|
||||||
|
@ -2108,6 +2139,18 @@ If we assume that
|
||||||
|
|
||||||
is chosen to represent the (rough) maximum tolerated magnitude of the summand
|
is chosen to represent the (rough) maximum tolerated magnitude of the summand
|
||||||
with regard to target accuracy.
|
with regard to target accuracy.
|
||||||
|
This adjustment means that, in worst-case scenario, with growing wavenumber
|
||||||
|
one has to include an increasing number of terms in the long-range sum
|
||||||
|
in order to achieve a given accuracy, the number of terms being proportional
|
||||||
|
to
|
||||||
|
\begin_inset Formula $\left|\kappa\right|^{d}$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
where
|
||||||
|
\begin_inset Formula $d$
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
is the dimension of the lattice.
|
||||||
|
|
||||||
\begin_inset Note Note
|
\begin_inset Note Note
|
||||||
status open
|
status open
|
||||||
|
@ -2228,8 +2271,8 @@ noprefix "false"
|
||||||
translation operator:
|
translation operator:
|
||||||
\begin_inset Formula
|
\begin_inset Formula
|
||||||
\begin{align}
|
\begin{align}
|
||||||
\vswfrtlm{\tau}lm\left(\kappa\vect r\right) & =\sum_{m'=-1}^{1}\tropr_{\tau lm;21m'}\left(\kappa\vect r\right)\vswfrtlm 21{m'}\left(0\right),\nonumber \\
|
\vswfrtlm{\tau}lm\left(\kappa\vect r\right) & =\sum_{m'=-1}^{1}\tropr_{\tau lm;21m'}\left(\kappa\vect r\right)\vswfrtlm21{m'}\left(0\right),\nonumber \\
|
||||||
\vswfouttlm{\tau}lm\left(\kappa\vect r\right) & =\sum_{m'=-1}^{1}\trops_{\tau lm;21m'}\left(\kappa\vect r\right)\vswfrtlm 21{m'}\left(0\right),\label{eq:VSWFs expressed as translated dipole waves}
|
\vswfouttlm{\tau}lm\left(\kappa\vect r\right) & =\sum_{m'=-1}^{1}\trops_{\tau lm;21m'}\left(\kappa\vect r\right)\vswfrtlm21{m'}\left(0\right),\label{eq:VSWFs expressed as translated dipole waves}
|
||||||
\end{align}
|
\end{align}
|
||||||
|
|
||||||
\end_inset
|
\end_inset
|
||||||
|
@ -2256,7 +2299,7 @@ noprefix "false"
|
||||||
\end_inset
|
\end_inset
|
||||||
|
|
||||||
and the fact that all the other regular VSWFs except for
|
and the fact that all the other regular VSWFs except for
|
||||||
\begin_inset Formula $\vswfrtlm 21{m'}$
|
\begin_inset Formula $\vswfrtlm21{m'}$
|
||||||
\end_inset
|
\end_inset
|
||||||
|
|
||||||
vanish at origin.
|
vanish at origin.
|
||||||
|
@ -2329,10 +2372,10 @@ status open
|
||||||
\begin_inset Formula
|
\begin_inset Formula
|
||||||
\begin{align*}
|
\begin{align*}
|
||||||
\vect E_{\mathrm{scat}}\left(\vect r\right) & =\sum_{\left(\vect n,\alpha\right)\in\mathcal{P}}\sum_{\tau lm}\outcoeffptlm{\vect n,\alpha}{\tau}lm\vect u_{\tau lm}\left(\kappa\left(\vect r-\text{\vect R_{\vect n}-\vect r_{\alpha}}\right)\right)\\
|
\vect E_{\mathrm{scat}}\left(\vect r\right) & =\sum_{\left(\vect n,\alpha\right)\in\mathcal{P}}\sum_{\tau lm}\outcoeffptlm{\vect n,\alpha}{\tau}lm\vect u_{\tau lm}\left(\kappa\left(\vect r-\text{\vect R_{\vect n}-\vect r_{\alpha}}\right)\right)\\
|
||||||
& =\sum_{\left(\vect n,\alpha\right)\in\mathcal{P}}\sum_{\tau lm}\outcoeffptlm{\vect 0,\alpha}{\tau}lme^{i\vect k\cdot\vect R_{\vect n}}\sum_{m'=-1}^{1}\trops_{\tau lm;21m'}\left(\kappa\left(\vect r-\text{\vect R_{\vect n}-\vect r_{\alpha}}\right)\right)\vswfrtlm 21{m'}\left(0\right)\\
|
& =\sum_{\left(\vect n,\alpha\right)\in\mathcal{P}}\sum_{\tau lm}\outcoeffptlm{\vect0,\alpha}{\tau}lme^{i\vect k\cdot\vect R_{\vect n}}\sum_{m'=-1}^{1}\trops_{\tau lm;21m'}\left(\kappa\left(\vect r-\text{\vect R_{\vect n}-\vect r_{\alpha}}\right)\right)\vswfrtlm21{m'}\left(0\right)\\
|
||||||
& =\sum_{\left(\vect n,\alpha\right)\in\mathcal{P}}\sum_{\tau lm}\outcoeffptlm{\vect 0,\alpha}{\tau}lme^{-i\vect k\cdot\vect R_{\vect n}}\sum_{m'=-1}^{1}\trops_{\tau lm;21m'}\left(\kappa\left(\vect r+\text{\vect R_{\vect n}-\vect r_{\alpha}}\right)\right)\vswfrtlm 21{m'}\left(0\right),\text{FIXME signs}\\
|
& =\sum_{\left(\vect n,\alpha\right)\in\mathcal{P}}\sum_{\tau lm}\outcoeffptlm{\vect0,\alpha}{\tau}lme^{-i\vect k\cdot\vect R_{\vect n}}\sum_{m'=-1}^{1}\trops_{\tau lm;21m'}\left(\kappa\left(\vect r+\text{\vect R_{\vect n}-\vect r_{\alpha}}\right)\right)\vswfrtlm21{m'}\left(0\right),\text{FIXME signs}\\
|
||||||
& =\sum_{\left(\vect n,\alpha\right)\in\mathcal{P}}\sum_{\tau lm}\outcoeffptlm{\vect 0,\alpha}{\tau}lme^{-i\vect k\cdot\vect R_{\vect n}}\sum_{m'=-1}^{1}\sum_{\lambda=\left|l-1\right|+\left|\tau-2\right|}^{l+1}\tropcoeff_{\tau lm;21m'}^{\lambda}\psi_{\lambda,m-m'}\left(\kappa\left(\vect r+\text{\vect R_{\vect n}-\vect r_{\alpha}}\right)\right)\vswfrtlm 21{m'}\left(0\right)\\
|
& =\sum_{\left(\vect n,\alpha\right)\in\mathcal{P}}\sum_{\tau lm}\outcoeffptlm{\vect0,\alpha}{\tau}lme^{-i\vect k\cdot\vect R_{\vect n}}\sum_{m'=-1}^{1}\sum_{\lambda=\left|l-1\right|+\left|\tau-2\right|}^{l+1}\tropcoeff_{\tau lm;21m'}^{\lambda}\psi_{\lambda,m-m'}\left(\kappa\left(\vect r+\text{\vect R_{\vect n}-\vect r_{\alpha}}\right)\right)\vswfrtlm21{m'}\left(0\right)\\
|
||||||
& =\sum_{\alpha\in\mathcal{P}_{1}}e^{-i\vect k\cdot\left(\vect r-\vect r_{\alpha}\right)}\sum_{\tau lm}\outcoeffptlm{\vect 0,\alpha}{\tau}lm\sum_{m'=-1}^{1}\sum_{\lambda=\left|l-1\right|+\left|\tau-2\right|}^{l+1}\tropcoeff_{\tau lm;21m'}^{\lambda}\sigma_{\lambda,m-m'}\left(\vect k,\vect r-\vect r_{\alpha}\right)
|
& =\sum_{\alpha\in\mathcal{P}_{1}}e^{-i\vect k\cdot\left(\vect r-\vect r_{\alpha}\right)}\sum_{\tau lm}\outcoeffptlm{\vect0,\alpha}{\tau}lm\sum_{m'=-1}^{1}\sum_{\lambda=\left|l-1\right|+\left|\tau-2\right|}^{l+1}\tropcoeff_{\tau lm;21m'}^{\lambda}\sigma_{\lambda,m-m'}\left(\vect k,\vect r-\vect r_{\alpha}\right)
|
||||||
\end{align*}
|
\end{align*}
|
||||||
|
|
||||||
\end_inset
|
\end_inset
|
||||||
|
@ -2350,7 +2393,7 @@ TODO fix signs and exponential phase factors
|
||||||
\begin_inset Formula
|
\begin_inset Formula
|
||||||
\begin{align*}
|
\begin{align*}
|
||||||
\vect E_{\mathrm{scat}}\left(\vect r\right) & =\sum_{\left(\vect n,\alpha\right)\in\mathcal{P}}\sum_{\tau lm}\outcoeffptlm{\vect n,\alpha}{\tau}lm\vect u_{\tau lm}\left(\kappa\left(\vect r-\text{\vect R_{\vect n}-\vect r_{\alpha}}\right)\right)\\
|
\vect E_{\mathrm{scat}}\left(\vect r\right) & =\sum_{\left(\vect n,\alpha\right)\in\mathcal{P}}\sum_{\tau lm}\outcoeffptlm{\vect n,\alpha}{\tau}lm\vect u_{\tau lm}\left(\kappa\left(\vect r-\text{\vect R_{\vect n}-\vect r_{\alpha}}\right)\right)\\
|
||||||
& =\sum_{\alpha\in\mathcal{P}_{1}}e^{-i\vect k\cdot\left(\vect r-\vect r_{\alpha}\right)}\sum_{\tau lm}\outcoeffptlm{\vect 0,\alpha}{\tau}lm\sum_{m'=-1}^{1}\sum_{\lambda=\left|l-1\right|+\left|\tau-2\right|}^{l+1}\tropcoeff_{\tau lm;21m'}^{\lambda}\sigma_{\lambda,m-m'}\left(\vect k,\vect r-\vect r_{\alpha}\right).
|
& =\sum_{\alpha\in\mathcal{P}_{1}}e^{-i\vect k\cdot\left(\vect r-\vect r_{\alpha}\right)}\sum_{\tau lm}\outcoeffptlm{\vect0,\alpha}{\tau}lm\sum_{m'=-1}^{1}\sum_{\lambda=\left|l-1\right|+\left|\tau-2\right|}^{l+1}\tropcoeff_{\tau lm;21m'}^{\lambda}\sigma_{\lambda,m-m'}\left(\vect k,\vect r-\vect r_{\alpha}\right).
|
||||||
\end{align*}
|
\end{align*}
|
||||||
|
|
||||||
\end_inset
|
\end_inset
|
||||||
|
|
|
@ -540,8 +540,18 @@ reference "sec:Applications"
|
||||||
|
|
||||||
\end_inset
|
\end_inset
|
||||||
|
|
||||||
shows some practical results that can be obtained using QPMS and benchmarks
|
shows some practical results that can be obtained using QPMS.
|
||||||
with BEM.
|
|
||||||
|
\begin_inset Note Note
|
||||||
|
status open
|
||||||
|
|
||||||
|
\begin_layout Plain Layout
|
||||||
|
and benchmarks with BEM.
|
||||||
|
\end_layout
|
||||||
|
|
||||||
|
\end_inset
|
||||||
|
|
||||||
|
|
||||||
\begin_inset Note Note
|
\begin_inset Note Note
|
||||||
status open
|
status open
|
||||||
|
|
||||||
|
|
Loading…
Reference in New Issue