662 lines
23 KiB
Plaintext
662 lines
23 KiB
Plaintext
#LyX 2.4 created this file. For more info see https://www.lyx.org/
|
|
\lyxformat 584
|
|
\begin_document
|
|
\begin_header
|
|
\save_transient_properties true
|
|
\origin unavailable
|
|
\textclass article
|
|
\use_default_options true
|
|
\maintain_unincluded_children false
|
|
\language finnish
|
|
\language_package default
|
|
\inputencoding utf8
|
|
\fontencoding auto
|
|
\font_roman "default" "default"
|
|
\font_sans "default" "default"
|
|
\font_typewriter "default" "default"
|
|
\font_math "auto" "auto"
|
|
\font_default_family default
|
|
\use_non_tex_fonts false
|
|
\font_sc false
|
|
\font_roman_osf false
|
|
\font_sans_osf false
|
|
\font_typewriter_osf false
|
|
\font_sf_scale 100 100
|
|
\font_tt_scale 100 100
|
|
\use_microtype false
|
|
\use_dash_ligatures true
|
|
\graphics default
|
|
\default_output_format default
|
|
\output_sync 0
|
|
\bibtex_command default
|
|
\index_command default
|
|
\float_placement class
|
|
\float_alignment class
|
|
\paperfontsize 10
|
|
\spacing single
|
|
\use_hyperref false
|
|
\papersize a3paper
|
|
\use_geometry true
|
|
\use_package amsmath 1
|
|
\use_package amssymb 1
|
|
\use_package cancel 1
|
|
\use_package esint 1
|
|
\use_package mathdots 1
|
|
\use_package mathtools 1
|
|
\use_package mhchem 1
|
|
\use_package stackrel 1
|
|
\use_package stmaryrd 1
|
|
\use_package undertilde 1
|
|
\cite_engine basic
|
|
\cite_engine_type default
|
|
\biblio_style plain
|
|
\use_bibtopic false
|
|
\use_indices false
|
|
\paperorientation portrait
|
|
\suppress_date false
|
|
\justification true
|
|
\use_refstyle 1
|
|
\use_minted 0
|
|
\use_lineno 0
|
|
\index Index
|
|
\shortcut idx
|
|
\color #008000
|
|
\end_index
|
|
\leftmargin 2cm
|
|
\topmargin 2cm
|
|
\rightmargin 2cm
|
|
\bottommargin 2cm
|
|
\secnumdepth 3
|
|
\tocdepth 3
|
|
\paragraph_separation indent
|
|
\paragraph_indentation default
|
|
\is_math_indent 0
|
|
\math_numbering_side default
|
|
\quotes_style english
|
|
\dynamic_quotes 0
|
|
\papercolumns 1
|
|
\papersides 1
|
|
\paperpagestyle default
|
|
\tablestyle default
|
|
\tracking_changes false
|
|
\output_changes false
|
|
\html_math_output 0
|
|
\html_css_as_file 0
|
|
\html_be_strict false
|
|
\end_header
|
|
|
|
\begin_body
|
|
|
|
\begin_layout Title
|
|
1D in 3D Ewald sum
|
|
\end_layout
|
|
|
|
\begin_layout Standard
|
|
\begin_inset FormulaMacro
|
|
\newcommand{\ud}{\mathrm{d}}
|
|
\end_inset
|
|
|
|
|
|
\begin_inset FormulaMacro
|
|
\newcommand{\abs}[1]{\left|#1\right|}
|
|
\end_inset
|
|
|
|
|
|
\begin_inset FormulaMacro
|
|
\newcommand{\vect}[1]{\mathbf{#1}}
|
|
\end_inset
|
|
|
|
|
|
\begin_inset FormulaMacro
|
|
\newcommand{\uvec}[1]{\hat{\mathbf{#1}}}
|
|
\end_inset
|
|
|
|
|
|
\lang english
|
|
|
|
\begin_inset FormulaMacro
|
|
\newcommand{\ush}[2]{Y_{#1}^{#2}}
|
|
\end_inset
|
|
|
|
|
|
\begin_inset FormulaMacro
|
|
\newcommand{\ushD}[2]{Y'_{#1}^{#2}}
|
|
\end_inset
|
|
|
|
|
|
\end_layout
|
|
|
|
\begin_layout Standard
|
|
\begin_inset FormulaMacro
|
|
\newcommand{\vsh}{\vect A}
|
|
\end_inset
|
|
|
|
|
|
\begin_inset FormulaMacro
|
|
\newcommand{\vshD}{\vect{A'}}
|
|
\end_inset
|
|
|
|
|
|
\begin_inset FormulaMacro
|
|
\newcommand{\wfkc}{\vect y}
|
|
\end_inset
|
|
|
|
|
|
\begin_inset FormulaMacro
|
|
\newcommand{\wfkcout}{\vect u}
|
|
\end_inset
|
|
|
|
|
|
\begin_inset FormulaMacro
|
|
\newcommand{\wfkcreg}{\vect v}
|
|
\end_inset
|
|
|
|
|
|
\begin_inset FormulaMacro
|
|
\newcommand{\wckcreg}{a}
|
|
\end_inset
|
|
|
|
|
|
\begin_inset FormulaMacro
|
|
\newcommand{\wckcout}{f}
|
|
\end_inset
|
|
|
|
|
|
\end_layout
|
|
|
|
\begin_layout Section
|
|
General formula
|
|
\end_layout
|
|
|
|
\begin_layout Standard
|
|
We need to find the expansion coefficient
|
|
\end_layout
|
|
|
|
\begin_layout Standard
|
|
\begin_inset Formula
|
|
\begin{equation}
|
|
\tau_{l'}^{m'}\left(\vect s,\vect k\right)=\frac{i}{\kappa j_{l'}\left(\kappa\left|\vect r\right|\right)}\int\ud\Omega_{\vect r}\,G_{\Lambda}^{(\kappa)}\left(\vect s+\vect r,\vect k\right)\ushD{l'}{m'}\left(\uvec r\right).\label{eq:tau extraction formula}
|
|
\end{equation}
|
|
|
|
\end_inset
|
|
|
|
|
|
\end_layout
|
|
|
|
\begin_layout Standard
|
|
[Linton, (2.24)] with slightly modified notation and setting
|
|
\begin_inset Formula $d_{c}=2$
|
|
\end_inset
|
|
|
|
:
|
|
\begin_inset Formula
|
|
\[
|
|
G_{\Lambda}^{(1;\kappa)}\left(\vect r\right)=-\frac{1}{2\pi^{d_{c}/2}\mathcal{A}}\sum_{\vect K\in\Lambda^{*}}e^{i\vect K\cdot\vect r}\int_{1/\eta}^{\infty e^{i\pi/4}}e^{-\kappa^{2}\gamma^{2}t^{2}/4}e^{-\left|\vect r^{\bot}\right|^{2}/t^{2}}t^{1-d_{c}}\ud t
|
|
\]
|
|
|
|
\end_inset
|
|
|
|
or, evaluated at point
|
|
\begin_inset Formula $\vect s+\vect r$
|
|
\end_inset
|
|
|
|
instead
|
|
\begin_inset Formula
|
|
\[
|
|
G_{\Lambda}^{(1;\kappa)}\left(\vect s+\vect r\right)=-\frac{1}{2\pi^{d_{c}/2}\mathcal{A}}\sum_{\vect K\in\Lambda^{*}}e^{i\vect K\cdot\left(\vect s+\vect r\right)}\int_{1/\eta}^{\infty e^{i\pi/4}}e^{-\kappa^{2}\gamma^{2}t^{2}/4}e^{-\left|\vect s^{\bot}+\vect r^{\bot}\right|^{2}/t^{2}}t^{1-d_{c}}\ud t
|
|
\]
|
|
|
|
\end_inset
|
|
|
|
The integral can be by substitutions taken into the form
|
|
\begin_inset Note Note
|
|
status open
|
|
|
|
\begin_layout Plain Layout
|
|
|
|
\lang english
|
|
\begin_inset Formula
|
|
\[
|
|
G_{\Lambda}^{\left(1\right)}\left(\vect r\right)=\frac{\pi^{-d_{c}/2}}{2\mathcal{A}}\sum_{\vect K_{m}\in\Lambda^{*}}e^{i\vect K_{m}\cdot\vect r}\int_{1/\eta}^{\infty\exp\left(i\pi/4\right)}e^{-\kappa^{2}\gamma_{m}^{2}\zeta^{2}/4}e^{-\left|\vect r_{\bot}\right|^{2}/\zeta^{2}}\zeta^{1-d_{c}}\ud\zeta
|
|
\]
|
|
|
|
\end_inset
|
|
|
|
Try substitution
|
|
\begin_inset Formula $t=\zeta^{2}$
|
|
\end_inset
|
|
|
|
: then
|
|
\begin_inset Formula $\ud t=2\zeta\,\ud\zeta$
|
|
\end_inset
|
|
|
|
(
|
|
\begin_inset Formula $\ud\zeta=\ud t/2t^{1/2}$
|
|
\end_inset
|
|
|
|
) and
|
|
\begin_inset Formula
|
|
\[
|
|
G_{\Lambda}^{\left(1\right)}\left(\vect r\right)=\frac{\pi^{-d_{c}/2}}{4\mathcal{A}}\sum_{\vect K_{m}\in\Lambda^{*}}e^{i\vect K_{m}\cdot\vect r}\int_{1/\eta^{2}}^{\infty\exp\left(i\pi/2\right)}e^{-\kappa^{2}\gamma_{m}^{2}t/4}e^{-\left|\vect r_{\bot}\right|^{2}/t}t^{\frac{-d_{c}}{2}}\ud t
|
|
\]
|
|
|
|
\end_inset
|
|
|
|
Try subst.
|
|
|
|
\begin_inset Formula $\tau=k^{2}\gamma_{m}^{2}/4$
|
|
\end_inset
|
|
|
|
|
|
\end_layout
|
|
|
|
\begin_layout Plain Layout
|
|
|
|
\lang english
|
|
\begin_inset Formula
|
|
\[
|
|
G_{\Lambda}^{\left(1\right)}\left(\vect r\right)=\frac{\pi^{-d_{c}/2}}{4\mathcal{A}}\sum_{\vect K_{m}\in\Lambda^{*}}e^{i\vect K_{m}\cdot\vect r}\left(\frac{\kappa\gamma_{m}}{2}\right)^{d_{c}}\int_{\kappa^{2}\gamma_{m}^{2}/4\eta^{2}}^{\infty\exp\left(i\pi/2\right)}e^{-\tau}e^{-\left|\vect r_{\bot}\right|^{2}\kappa^{2}\gamma_{m}^{2}/4\tau}\tau^{\frac{-d_{c}}{2}}\ud\tau
|
|
\]
|
|
|
|
\end_inset
|
|
|
|
|
|
\end_layout
|
|
|
|
\end_inset
|
|
|
|
|
|
\begin_inset Formula
|
|
\[
|
|
G_{\Lambda}^{(1;\kappa)}\left(\vect s+\vect r\right)=-\frac{1}{2\pi^{d_{c}/2}\mathcal{A}}\sum_{\vect K\in\Lambda^{*}}e^{i\vect K\cdot\left(\vect s+\vect r\right)}\int_{\kappa^{2}\gamma_{m}^{2}/4\eta^{2}}^{\infty\exp\left(i\pi/2\right)}e^{-\tau}e^{-\left|\vect s_{\bot}+\vect r_{\bot}\right|^{2}\kappa^{2}\gamma_{m}^{2}/4\tau}\tau^{-\frac{d_{c}}{2}}\ud\tau
|
|
\]
|
|
|
|
\end_inset
|
|
|
|
|
|
\end_layout
|
|
|
|
\begin_layout Standard
|
|
\begin_inset Foot
|
|
status open
|
|
|
|
\begin_layout Plain Layout
|
|
[Linton, (2.25)] with slightly modified notation:
|
|
\begin_inset Formula
|
|
\[
|
|
G_{\Lambda}^{(1;\kappa)}\left(\vect r\right)=-\frac{1}{\sqrt{4\pi}\mathcal{A}}\sum_{\vect K\in\Lambda^{*}}e^{i\vect K\cdot\vect r}\sum_{j=0}^{\infty}\frac{\left(-1\right)^{j}\left|\vect r^{\bot}\right|^{2j}}{j!}\left(\frac{\kappa\gamma_{\vect K}}{2}\right)^{2j-1}\Gamma_{j\vect K}
|
|
\]
|
|
|
|
\end_inset
|
|
|
|
We want to express an expansion in a shifted point, so let's substitute
|
|
|
|
\begin_inset Formula $\vect r\to\vect s+\vect r$
|
|
\end_inset
|
|
|
|
|
|
\begin_inset Formula
|
|
\[
|
|
G_{\Lambda}^{(1;\kappa)}\left(\vect s+\vect r\right)=-\frac{1}{\sqrt{4\pi}\mathcal{A}}\sum_{\vect K\in\Lambda^{*}}e^{i\vect K\cdot\left(\vect s+\vect r\right)}\sum_{j=0}^{\infty}\frac{\left(-1\right)^{j}\left|\vect s^{\bot}+\vect r^{\bot}\right|^{2j}}{j!}\left(\frac{\kappa\gamma_{\vect K}}{2}\right)^{2j-1}\Gamma_{j\vect K}
|
|
\]
|
|
|
|
\end_inset
|
|
|
|
|
|
\end_layout
|
|
|
|
\end_inset
|
|
|
|
Let's do the integration to get
|
|
\begin_inset Formula $\tau_{l}^{m}\left(\vect s,\vect k\right)$
|
|
\end_inset
|
|
|
|
|
|
\begin_inset Formula
|
|
\[
|
|
\int\ud\Omega_{\vect r}\,G_{\Lambda}^{(1;\kappa)}\left(\vect s+\vect r\right)\ushD{l'}{m'}\left(\uvec r\right)=-\frac{1}{2\pi^{d_{c}/2}\mathcal{A}}\int\ud\Omega_{\vect r}\,\ushD{l'}{m'}\left(\uvec r\right)\sum_{\vect K\in\Lambda^{*}}e^{i\vect K\cdot\left(\vect s+\vect r\right)}\int_{\kappa^{2}\gamma_{\vect K}^{2}/4\eta^{2}}^{\infty\exp\left(i\pi/2\right)}e^{-\tau}e^{-\left|\vect s_{\bot}+\vect r_{\bot}\right|^{2}\kappa^{2}\gamma_{\vect K}^{2}/4\tau}\tau^{-\frac{d_{c}}{2}}\ud\tau
|
|
\]
|
|
|
|
\end_inset
|
|
|
|
The
|
|
\begin_inset Formula $\vect r$
|
|
\end_inset
|
|
|
|
-dependent plane wave factor can be also written as
|
|
\begin_inset Formula
|
|
\begin{align*}
|
|
e^{i\vect K\cdot\vect r} & =e^{i\left|\vect K\right|\vect r\cdot\uvec K}=4\pi\sum_{lm}i^{l}\mathcal{J}'_{l}^{m}\left(\left|\vect K\right|\vect r\right)\ush lm\left(\uvec K\right)\\
|
|
& =4\pi\sum_{lm}i^{l}j_{l}\left(\left|\vect K\right|\left|\vect r\right|\right)\ushD lm\left(\uvec{\vect r}\right)\ush lm\left(\uvec K\right)
|
|
\end{align*}
|
|
|
|
\end_inset
|
|
|
|
|
|
\begin_inset Note Note
|
|
status open
|
|
|
|
\begin_layout Plain Layout
|
|
or the other way around
|
|
\begin_inset Formula
|
|
\[
|
|
e^{i\vect K\cdot\vect r}=4\pi\sum_{lm}i^{l}j_{l}\left(\left|\vect K\right|\left|\vect r\right|\right)\ush lm\left(\uvec{\vect r}\right)\ushD lm\left(\uvec K\right)
|
|
\]
|
|
|
|
\end_inset
|
|
|
|
|
|
\end_layout
|
|
|
|
\end_inset
|
|
|
|
so
|
|
\begin_inset Formula
|
|
\[
|
|
\int\ud\Omega_{\vect r}\,G_{\Lambda}^{(1;\kappa)}\left(\vect s+\vect r\right)\ushD{l'}{m'}\left(\uvec r\right)=-\frac{1}{2\pi^{d_{c}/2}\mathcal{A}}\int\ud\Omega_{\vect r}\,\ushD{l'}{m'}\left(\uvec r\right)\frac{1}{2\pi\mathcal{A}}\sum_{\vect K\in\Lambda^{*}}e^{i\vect K\cdot\vect s}\sum_{lm}4\pi i^{l}j_{l}\left(\left|\vect K\right|\left|\vect r\right|\right)\ushD lm\left(\uvec r\right)\ush lm\left(\uvec K\right)\int_{\kappa^{2}\gamma_{\vect K}^{2}/4\eta^{2}}^{\infty\exp\left(i\pi/2\right)}e^{-\tau}e^{-\left|\vect s_{\bot}+\vect r_{\bot}\right|^{2}\kappa^{2}\gamma_{\vect K}^{2}/4\tau}\tau^{-\frac{d_{c}}{2}}\ud\tau
|
|
\]
|
|
|
|
\end_inset
|
|
|
|
|
|
\end_layout
|
|
|
|
\begin_layout Standard
|
|
We also have
|
|
\begin_inset Formula
|
|
\begin{align*}
|
|
e^{-\left|\vect s_{\bot}+\vect r_{\bot}\right|^{2}\kappa^{2}\gamma_{\vect K}^{2}/4\tau} & =e^{-\left(\left|\vect s_{\bot}\right|^{2}+\left|\vect r_{\bot}\right|^{2}+2\vect r_{\bot}\cdot\vect s_{\bot}\right)\kappa^{2}\gamma_{\vect K}^{2}/4\tau}\\
|
|
& =e^{-\left|\vect s_{\bot}\right|^{2}\kappa^{2}\gamma_{\vect K}^{2}/4\tau}\sum_{n=0}^{\infty}\frac{1}{n!}\left(-\frac{\left(\left|\vect r_{\bot}\right|^{2}+2\vect r_{\bot}\cdot\vect s_{\bot}\right)\kappa^{2}\gamma_{\vect K}^{2}}{4\tau}\right)^{n},
|
|
\end{align*}
|
|
|
|
\end_inset
|
|
|
|
hence
|
|
\begin_inset Formula
|
|
\begin{align*}
|
|
\int\ud\Omega_{\vect r}\,G_{\Lambda}^{(1;\kappa)}\left(\vect s+\vect r\right)\ushD{l'}{m'}\left(\uvec r\right) & =-\frac{1}{2\pi^{d_{c}/2}\mathcal{A}}\int\ud\Omega_{\vect r}\,\ushD{l'}{m'}\left(\uvec r\right)\sum_{\vect K\in\Lambda^{*}}e^{i\vect K\cdot\vect s}\sum_{lm}4\pi i^{l}j_{l}\left(\left|\vect K\right|\left|\vect r\right|\right)\ushD lm\left(\uvec r\right)\ush lm\left(\uvec K\right)\sum_{n=0}^{\infty}\frac{1}{n!}\left(-\frac{\left(\left|\vect r_{\bot}\right|^{2}+2\vect r_{\bot}\cdot\vect s_{\bot}\right)\kappa^{2}\gamma_{\vect K}^{2}}{4}\right)^{n}\underbrace{\int_{\kappa^{2}\gamma_{\vect K}^{2}/4\eta^{2}}^{\infty\exp\left(i\pi/2\right)}e^{-\tau}e^{-\left|\vect s_{\bot}\right|^{2}\kappa^{2}\gamma_{\vect K}^{2}/4\tau}\tau^{-\frac{d_{c}}{2}-n}\ud\tau}_{\Delta_{n}^{\left(d_{\Lambda}\right)}}\\
|
|
& =-\frac{1}{2\pi^{d_{c}/2}\mathcal{A}}\sum_{\vect K\in\Lambda^{*}}e^{i\vect K\cdot\vect s}\sum_{lm}4\pi i^{l}j_{l}\left(\left|\vect K\right|\left|\vect r\right|\right)\ush lm\left(\uvec K\right)\sum_{n=0}^{\infty}\frac{\Delta_{n}^{\left(d_{\Lambda}\right)}}{n!}\int\ud\Omega_{\vect r}\,\ushD{l'}{m'}\left(\uvec r\right)\ushD lm\left(\uvec r\right)\left(-\frac{\left(\left|\vect r_{\bot}\right|^{2}+2\vect r_{\bot}\cdot\vect s_{\bot}\right)\kappa^{2}\gamma_{\vect K}^{2}}{4}\right)^{n}\\
|
|
& =-\frac{1}{2\pi^{d_{c}/2}\mathcal{A}}\sum_{\vect K\in\Lambda^{*}}e^{i\vect K\cdot\vect s}\sum_{lm}4\pi i^{l}j_{l}\left(\left|\vect K\right|\left|\vect r\right|\right)\ush lm\left(\uvec K\right)\sum_{n=0}^{\infty}\frac{\left(-1\right)^{n}}{n!}\Delta_{n}^{\left(d_{\Lambda}\right)}\left(\frac{\kappa\gamma_{\vect K}}{2}\right)^{2n}\sum_{k=0}^{n}\int\ud\Omega_{\vect r}\,\ushD{l'}{m'}\left(\uvec r\right)\ushD lm\left(\uvec r\right)\left|\vect r_{\bot}\right|^{2(n-k)}\left(2\vect r_{\bot}\cdot\vect s_{\bot}\right)^{k}
|
|
\end{align*}
|
|
|
|
\end_inset
|
|
|
|
If we label
|
|
\begin_inset Formula $\left|\vect r_{\bot}\right|\left|\vect s_{\bot}\right|\cos\varphi\equiv\vect r_{\bot}\cdot\vect s_{\bot}$
|
|
\end_inset
|
|
|
|
, we have
|
|
\begin_inset Formula
|
|
\[
|
|
\int\ud\Omega_{\vect r}\,G_{\Lambda}^{(1;\kappa)}\left(\vect s+\vect r\right)\ushD{l'}{m'}\left(\uvec r\right)=-\frac{1}{2\pi^{d_{c}/2}\mathcal{A}}\sum_{\vect K\in\Lambda^{*}}e^{i\vect K\cdot\vect s}\sum_{lm}4\pi i^{l}j_{l}\left(\left|\vect K\right|\left|\vect r\right|\right)\ush lm\left(\uvec K\right)\sum_{n=0}^{\infty}\frac{\left(-1\right)^{n}}{n!}\Delta_{n}^{\left(d_{\Lambda}\right)}\left(\frac{\kappa\gamma_{\vect K}}{2}\right)^{2n}\sum_{k=0}^{n}\left(2\left|\vect s_{\bot}\right|\right)^{k}\int\ud\Omega_{\vect r}\,\ushD{l'}{m'}\left(\uvec r\right)\ushD lm\left(\uvec r\right)\left|\vect r_{\bot}\right|^{2n-k}\left(\cos\varphi\right)^{k}
|
|
\]
|
|
|
|
\end_inset
|
|
|
|
and if we label
|
|
\begin_inset Formula $\left|\vect r\right|\sin\vartheta\equiv\left|\vect r_{\bot}\right|$
|
|
\end_inset
|
|
|
|
|
|
\begin_inset Formula
|
|
\[
|
|
\int\ud\Omega_{\vect r}\,G_{\Lambda}^{(1;\kappa)}\left(\vect s+\vect r\right)\ushD{l'}{m'}\left(\uvec r\right)=-\frac{1}{2\pi^{d_{c}/2}\mathcal{A}}\sum_{\vect K\in\Lambda^{*}}e^{i\vect K\cdot\vect s}\sum_{lm}4\pi i^{l}j_{l}\left(\left|\vect K\right|\left|\vect r\right|\right)\ush lm\left(\uvec K\right)\sum_{n=0}^{\infty}\frac{\left(-1\right)^{n}}{n!}\Delta_{n}^{\left(d_{\Lambda}\right)}\left(\frac{\kappa\gamma_{\vect K}}{2}\right)^{2n}\sum_{k=0}^{n}\left|\vect r\right|^{2n-k}\left(2\left|\vect s_{\bot}\right|\right)^{k}\int\ud\Omega_{\vect r}\,\ushD{l'}{m'}\left(\uvec r\right)\ushD lm\left(\uvec r\right)\left(\sin\vartheta\right)^{2n-k}\left(\cos\varphi\right)^{k}
|
|
\]
|
|
|
|
\end_inset
|
|
|
|
Now let's put the RHS into
|
|
\begin_inset CommandInset ref
|
|
LatexCommand eqref
|
|
reference "eq:tau extraction formula"
|
|
plural "false"
|
|
caps "false"
|
|
noprefix "false"
|
|
|
|
\end_inset
|
|
|
|
and try eliminating some sum by taking the limit
|
|
\begin_inset Formula $\left|\vect r\right|\to0$
|
|
\end_inset
|
|
|
|
.
|
|
We have
|
|
\begin_inset Formula $j_{l}\left(\left|\vect K\right|\left|\vect r\right|\right)\sim\left(\left|\vect K\right|\left|\vect r\right|\right)^{l}/\left(2l+1\right)!!$
|
|
\end_inset
|
|
|
|
; the denominator from
|
|
\begin_inset CommandInset ref
|
|
LatexCommand eqref
|
|
reference "eq:tau extraction formula"
|
|
plural "false"
|
|
caps "false"
|
|
noprefix "false"
|
|
|
|
\end_inset
|
|
|
|
behaves like
|
|
\begin_inset Formula $j_{l'}\left(\kappa\left|\vect r\right|\right)\sim\left(\kappa\left|\vect r\right|\right)^{l'}/\left(2l'+1\right)!!.$
|
|
\end_inset
|
|
|
|
The leading terms are hence those with
|
|
\begin_inset Formula $\left|\vect r\right|^{l-l'+2n-k}$
|
|
\end_inset
|
|
|
|
.
|
|
So
|
|
\begin_inset Formula
|
|
\[
|
|
\tau_{l'}^{m'}\left(\vect s,\vect k\right)=\frac{-i}{2\pi^{d_{c}/2}\mathcal{A}\kappa^{1+l'}}\left(2l'+1\right)!!\sum_{\vect K\in\Lambda^{*}}e^{i\vect K\cdot\vect s}\sum_{lm}4\pi i^{l}\frac{\left|\vect K\right|^{l}}{\left(2l+1\right)!!}\ush lm\left(\uvec K\right)\sum_{n=0}^{\infty}\frac{\left(-1\right)^{n}}{n!}\Delta_{n}^{\left(d_{\Lambda}\right)}\left(\frac{\kappa\gamma_{\vect K}}{2}\right)^{2n}\sum_{k=0}^{n}\delta_{l'-l,2n-k}\left(2\left|\vect s_{\bot}\right|\right)^{k}\int\ud\Omega_{\vect r}\,\ushD{l'}{m'}\left(\uvec r\right)\ushD lm\left(\uvec r\right)\left(\sin\vartheta\right)^{l'-l}\left(\cos\varphi\right)^{k}.
|
|
\]
|
|
|
|
\end_inset
|
|
|
|
Let's now focus on rearranging the sums; we have
|
|
\begin_inset Formula
|
|
\[
|
|
S(l')\equiv\sum_{l=0}^{\infty}\sum_{n=0}^{\infty}\sum_{k=0}^{n}\delta_{l'-l,2n-k}f(l',l,n,k)=\sum_{l=0}^{\infty}\sum_{n=0}^{\infty}\sum_{k=0}^{n}\delta_{l'-l,2n-k}f(l',l,n,2n-l'+l)
|
|
\]
|
|
|
|
\end_inset
|
|
|
|
We have
|
|
\begin_inset Formula $0\le k\le n$
|
|
\end_inset
|
|
|
|
, hence
|
|
\begin_inset Formula $0\le2n-l'+l\le n$
|
|
\end_inset
|
|
|
|
, hence
|
|
\begin_inset Formula $-2n\le-l'+l\le-n$
|
|
\end_inset
|
|
|
|
, hence also
|
|
\begin_inset Formula $l'-2n\le l\le l'-n$
|
|
\end_inset
|
|
|
|
, which gives the opportunity to swap the
|
|
\begin_inset Formula $l,n$
|
|
\end_inset
|
|
|
|
sums and the
|
|
\begin_inset Formula $l$
|
|
\end_inset
|
|
|
|
-sum becomes finite; so also consuming
|
|
\begin_inset Formula $\sum_{k=0}^{n}\delta_{l'-l,2n-k}$
|
|
\end_inset
|
|
|
|
we get
|
|
\begin_inset Formula
|
|
\[
|
|
S(l')=\sum_{n=0}^{\infty}\sum_{l=\max(0,l'-2n)}^{l'-n}f(l',l,n,2n-l'+l).
|
|
\]
|
|
|
|
\end_inset
|
|
|
|
Finally, we see that the interval of valid
|
|
\begin_inset Formula $l$
|
|
\end_inset
|
|
|
|
becomes empty when
|
|
\begin_inset Formula $l'-n<0$
|
|
\end_inset
|
|
|
|
, i.e.
|
|
|
|
\begin_inset Formula $n>l'$
|
|
\end_inset
|
|
|
|
; so we get a finite sum
|
|
\begin_inset Formula
|
|
\[
|
|
S(l')=\sum_{n=0}^{l'}\sum_{l=\max(0,l'-2n)}^{l'-n}f(l',l,n,2n-l'+l).
|
|
\]
|
|
|
|
\end_inset
|
|
|
|
Applying rearrangement,
|
|
\begin_inset Formula
|
|
\[
|
|
\tau_{l'}^{m'}\left(\vect s,\vect k\right)=\frac{-i}{2\pi^{d_{c}/2}\mathcal{A}\kappa}\frac{\left(2l'+1\right)!!}{\kappa^{l'}}\sum_{\vect K\in\Lambda^{*}}e^{i\vect K\cdot\vect s}\sum_{n=0}^{l'}\frac{\left(-1\right)^{n}}{n!}\Delta_{n}^{\left(d_{\Lambda}\right)}\left(\frac{\kappa\gamma_{\vect K}}{2}\right)^{2n}\sum_{l=\max\left(0,l'-2n\right)}^{l'-n}4\pi i^{l}\left(2\left|\vect s_{\bot}\right|\right)^{2n-l'+l}\frac{\left|\vect K\right|^{l}}{\left(2l+1\right)!!}\sum_{m=-l}^{l}\ush lm\left(\uvec K\right)\int\ud\Omega_{\vect r}\,\ushD{l'}{m'}\left(\uvec r\right)\ushD lm\left(\uvec r\right)\left(\sin\vartheta\right)^{l'-l}\left(\cos\varphi\right)^{2n-l'+l},
|
|
\]
|
|
|
|
\end_inset
|
|
|
|
or replacing the anles with their original definition,
|
|
\begin_inset Formula
|
|
\[
|
|
\tau_{l'}^{m'}\left(\vect s,\vect k\right)=\frac{-i}{2\pi^{d_{c}/2}\mathcal{A}\kappa}\frac{\left(2l'+1\right)!!}{\kappa^{l'}}\sum_{\vect K\in\Lambda^{*}}e^{i\vect K\cdot\vect s}\sum_{n=0}^{l'}\frac{\left(-1\right)^{n}}{n!}\Delta_{n}^{\left(d_{\Lambda}\right)}\left(\frac{\kappa\gamma_{\vect K}}{2}\right)^{2n}\sum_{l=\max\left(0,l'-2n\right)}^{l'-n}4\pi i^{l}\left(2\left|\vect s_{\bot}\right|\right)^{2n-l'+l}\frac{\left|\vect K\right|^{l}}{\left(2l+1\right)!!}\sum_{m=-l}^{l}\ush lm\left(\uvec K\right)\int\ud\Omega_{\vect r}\,\ushD{l'}{m'}\left(\uvec r\right)\ushD lm\left(\uvec r\right)\left(\frac{\left|\vect r_{\bot}\right|}{\left|\vect r\right|}\right)^{l'-l}\left(\frac{\vect r_{\bot}\cdot\vect s_{\bot}}{\left|\vect r_{\bot}\right|\left|\vect s_{\bot}\right|}\right)^{2n-l'+l},
|
|
\]
|
|
|
|
\end_inset
|
|
|
|
and if we want a
|
|
\begin_inset Formula $\sigma_{l'}^{m'}\left(\vect s,\vect k\right)$
|
|
\end_inset
|
|
|
|
instead, we reverse the sign of
|
|
\begin_inset Formula $\vect s$
|
|
\end_inset
|
|
|
|
and replace all spherical harmonics with their dual counterparts:
|
|
\begin_inset Formula
|
|
\[
|
|
\sigma_{l'}^{m'}\left(\vect s,\vect k\right)=\frac{-i}{2\pi^{d_{c}/2}\mathcal{A}\kappa}\frac{\left(2l'+1\right)!!}{\kappa^{l'}}\sum_{\vect K\in\Lambda^{*}}e^{-i\vect K\cdot\vect s}\sum_{n=0}^{l'}\frac{\left(-1\right)^{n}}{n!}\Delta_{n}^{\left(d_{\Lambda}\right)}\left(\frac{\kappa\gamma_{\vect K}}{2}\right)^{2n}\sum_{l=\max\left(0,l'-2n\right)}^{l'-n}4\pi i^{l}\left(2\left|\vect s_{\bot}\right|\right)^{2n-l'+l}\frac{\left|\vect K\right|^{l}}{\left(2l+1\right)!!}\sum_{m=-l}^{l}\ushD lm\left(\uvec K\right)\int\ud\Omega_{\vect r}\,\ush{l'}{m'}\left(\uvec r\right)\ush lm\left(\uvec r\right)\left(\frac{\left|\vect r_{\bot}\right|}{\left|\vect r\right|}\right)^{l'-l}\left(\frac{-\vect r_{\bot}\cdot\vect s_{\bot}}{\left|\vect r_{\bot}\right|\left|\vect s_{\bot}\right|}\right)^{2n-l'+l},
|
|
\]
|
|
|
|
\end_inset
|
|
|
|
and remembering that in the plane wave expansion the
|
|
\begin_inset Quotes eld
|
|
\end_inset
|
|
|
|
duality
|
|
\begin_inset Quotes erd
|
|
\end_inset
|
|
|
|
is interchangeable,
|
|
\begin_inset Formula
|
|
\[
|
|
\sigma_{l'}^{m'}\left(\vect s,\vect k\right)=\frac{-i}{2\pi^{d_{c}/2}\mathcal{A}\kappa}\frac{\left(2l'+1\right)!!}{\kappa^{l'}}\sum_{\vect K\in\Lambda^{*}}e^{-i\vect K\cdot\vect s}\sum_{n=0}^{l'}\frac{\left(-1\right)^{n}}{n!}\Delta_{n}^{\left(d_{\Lambda}\right)}\left(\frac{\kappa\gamma_{\vect K}}{2}\right)^{2n}\sum_{l=\max\left(0,l'-2n\right)}^{l'-n}4\pi i^{l}\left(2\left|\vect s_{\bot}\right|\right)^{2n-l'+l}\frac{\left|\vect K\right|^{l}}{\left(2l+1\right)!!}\sum_{m=-l}^{l}\ush lm\left(\uvec K\right)\underbrace{\int\ud\Omega_{\vect r}\,\ush{l'}{m'}\left(\uvec r\right)\ushD lm\left(\uvec r\right)\left(\frac{\left|\vect r_{\bot}\right|}{\left|\vect r\right|}\right)^{l'-l}\left(\frac{-\vect r_{\bot}\cdot\vect s_{\bot}}{\left|\vect r_{\bot}\right|\left|\vect s_{\bot}\right|}\right)^{2n-l'+l}}_{\equiv A_{l',l,m',m,n}^{\left(d_{\Lambda}\right)}}.
|
|
\]
|
|
|
|
\end_inset
|
|
|
|
The angular integral is easier to evaluate when
|
|
\begin_inset Formula $d_{\Lambda}=2$
|
|
\end_inset
|
|
|
|
, because then
|
|
\begin_inset Formula $\vect r_{\bot}$
|
|
\end_inset
|
|
|
|
is parallel (or antiparallel) to
|
|
\begin_inset Formula $\vect s_{\bot}$
|
|
\end_inset
|
|
|
|
, which gives
|
|
\begin_inset Formula
|
|
\[
|
|
A_{l',l,m',m,n}^{\left(2\right)}=\left(-\frac{\vect r_{\bot}\cdot\vect s_{\bot}}{\left|\vect r_{\bot}\cdot\vect s_{\bot}\right|}\right)^{2n-l'+l}\int\ud\Omega_{\vect r}\,\ush{l'}{m'}\left(\uvec r\right)\ushD lm\left(\uvec r\right)\left(\frac{\left|\vect r_{\bot}\right|}{\left|\vect r\right|}\right)^{2n}
|
|
\]
|
|
|
|
\end_inset
|
|
|
|
and if we set the normal of the lattice correspond to the
|
|
\begin_inset Formula $z$
|
|
\end_inset
|
|
|
|
axis, the azimuthal part of the integral will become zero unless
|
|
\begin_inset Formula $m'=m$
|
|
\end_inset
|
|
|
|
for any meaningful spherical harmonics convention, and the polar part for
|
|
the only nonzero case has a closed-form expression, see e.g.
|
|
[Linton (A.15)], so one arrives at an expression similar to [Kambe II, (3.15)]
|
|
\lang english
|
|
|
|
\begin_inset Formula
|
|
\begin{multline}
|
|
\sigma_{l,m}^{\left(\mathrm{L},\eta\right)}\left(\vect k,\vect s\right)=-\frac{i^{l+1}}{\kappa^{2}\mathcal{A}}\pi^{3/2}2\left(\left(l-m\right)/2\right)!\left(\left(l+m\right)/2\right)!\times\\
|
|
\times\sum_{\vect K\in\Lambda^{*}}e^{i\vect K\cdot\vect s}\ush lm\left(\vect k+\vect K\right)\sum_{j=0}^{l-\left|m\right|}\left(-1\right)^{j}\gamma_{\vect K}^{2}^{2j+1}\times\\
|
|
\times\Delta_{j}\left(\frac{\kappa^{2}\gamma_{\vect K}^{2}}{4\eta^{2}},-i\kappa\gamma_{\vect K}^{2}s_{\perp}\right)\times\\
|
|
\times\sum_{\substack{s\\
|
|
j\le s\le\min\left(2j,l-\left|m\right|\right)\\
|
|
l-n+\left|m\right|\,\mathrm{even}
|
|
}
|
|
}\frac{1}{\left(2j-s\right)!\left(s-j\right)!}\frac{\left(-\kappa s_{\perp}\right)^{2j-s}\left(\left|\vect k+\vect K\right|/\kappa\right)^{l-s}}{\left(\frac{1}{2}\left(l-m-s\right)\right)!\left(\frac{1}{2}\left(l+m-s\right)\right)!}\label{eq:Ewald in 3D long-range part 1D 2D-1}
|
|
\end{multline}
|
|
|
|
\end_inset
|
|
|
|
where
|
|
\begin_inset Formula $s_{\perp}\equiv\vect s\cdot\uvec z=\vect s_{\bot}\cdot\uvec z$
|
|
\end_inset
|
|
|
|
.
|
|
If
|
|
\begin_inset Formula $d_{\Lambda}=1$
|
|
\end_inset
|
|
|
|
, the angular becomes more complicated to evaluate due to the different
|
|
behaviour of the
|
|
\begin_inset Formula $\vect r_{\bot}\cdot\vect s_{\bot}/\left|\vect r_{\bot}\right|\left|\vect s_{\bot}\right|$
|
|
\end_inset
|
|
|
|
factor.
|
|
The choice of coordinates can make most of the terms dissapear: if the
|
|
lattice is set parallel to the
|
|
\begin_inset Formula $z$
|
|
\end_inset
|
|
|
|
axis,
|
|
\begin_inset Formula $A_{l',l,m',m,n}^{\left(1\right)}$
|
|
\end_inset
|
|
|
|
is zero unless
|
|
\begin_inset Formula $m=0$
|
|
\end_inset
|
|
|
|
, but one still has
|
|
\begin_inset Formula
|
|
\[
|
|
A_{l',l,m',0,n}^{\left(1\right)}=\pi\delta_{m',l'-l-2n}\lambda'_{l0}\lambda_{l'm'}\int_{-1}^{1}\ud x\,P_{l'}^{m'}\left(x\right)P_{l}^{0}\left(x\right)\left(1-x^{2}\right)^{\frac{l'-l}{2}}
|
|
\]
|
|
|
|
\end_inset
|
|
|
|
where
|
|
\begin_inset Formula $\lambda_{lm}$
|
|
\end_inset
|
|
|
|
are constants depending on the conventions for spherical harmonics.
|
|
This does not seem to have such a nice closed-form expression as in the
|
|
2D case, but it can be evaluated e.g.
|
|
using the common recurrence relations for associated Legendre polynomials.
|
|
\end_layout
|
|
|
|
\end_body
|
|
\end_document
|