This commit is contained in:
sarasbbg 2023-04-03 11:21:58 +02:00
parent 0512705c14
commit 5f67b1f630
13 changed files with 19146 additions and 0 deletions

18331
HKvsLieb.bib Normal file

File diff suppressed because it is too large Load Diff

View File

@ -0,0 +1,58 @@
% Gemini theme
% https://github.com/anishathalye/gemini
% ====================
% Definitions
% ====================
\definecolor{lightgray}{RGB}{245, 246, 250}
\definecolor{blue}{RGB}{64, 115, 158}
\definecolor{darkblue}{RGB}{39, 60, 117}
\definecolor{lightblue}{RGB}{232, 244, 255}
% ====================
% Theme
% ====================
% Basic colors
\setbeamercolor{palette primary}{fg=black,bg=white}
\setbeamercolor{palette secondary}{fg=black,bg=white}
\setbeamercolor{palette tertiary}{bg=black,fg=white}
\setbeamercolor{palette quaternary}{fg=black,bg=white}
\setbeamercolor{structure}{fg=darkblue}
% Headline
\setbeamercolor{headline}{fg=lightgray,bg=blue}
\setbeamercolor{headline rule}{bg=darkblue}
% Block
\setbeamercolor{block title}{fg=blue,bg=white}
\setbeamercolor{block separator}{bg=black}
\setbeamercolor{block body}{fg=black,bg=white}
% Alert Block
\setbeamercolor{block alerted title}{fg=blue,bg=lightblue}
\setbeamercolor{block alerted separator}{bg=black}
\setbeamercolor{block alerted body}{fg=black,bg=lightblue}
% Example Block
\setbeamercolor{block example title}{fg=blue,bg=lightgray}
\setbeamercolor{block example separator}{bg=black}
\setbeamercolor{block example body}{fg=black,bg=lightgray}
% Heading
\setbeamercolor{heading}{fg=black}
% Itemize
\setbeamercolor{item}{fg=darkblue}
% Bibliography
\setbeamercolor{bibliography item}{fg=black}
\setbeamercolor{bibliography entry author}{fg=black}
\setbeamercolor{bibliography entry title}{fg=black}
\setbeamercolor{bibliography entry location}{fg=black}
\setbeamercolor{bibliography entry note}{fg=black}
\setbeamertemplate{bibliography entry article}{}
\setbeamertemplate{bibliography entry title}{}
\setbeamertemplate{bibliography entry location}{}
\setbeamertemplate{bibliography entry note}{}

View File

@ -0,0 +1,55 @@
% Gemini theme
% https://github.com/anishathalye/gemini
% ====================
% Definitions
% ====================
\definecolor{labsixorange}{RGB}{243, 111, 33}
% Extra colors
\definecolor{lightgray}{RGB}{240, 240, 240}
\definecolor{lightorange}{RGB}{255, 240, 230}
% ====================
% Theme
% ====================
% Basic colors
\setbeamercolor{palette primary}{fg=black,bg=white}
\setbeamercolor{palette secondary}{fg=black,bg=white}
\setbeamercolor{palette tertiary}{bg=black,fg=white}
\setbeamercolor{palette quaternary}{fg=black,bg=white}
\setbeamercolor{structure}{fg=labsixorange}
% Headline
\setbeamercolor{headline}{fg=white,bg=labsixorange}
\setbeamercolor{headline rule}{bg=black}
% Block
\setbeamercolor{block title}{fg=labsixorange,bg=white}
\setbeamercolor{block separator}{bg=black}
\setbeamercolor{block body}{fg=black,bg=white}
% Alert Block
\setbeamercolor{block alerted title}{fg=labsixorange,bg=lightorange}
\setbeamercolor{block alerted separator}{bg=black}
\setbeamercolor{block alerted body}{fg=black,bg=lightorange}
% Example Block
\setbeamercolor{block example title}{fg=labsixorange,bg=lightgray}
\setbeamercolor{block example separator}{bg=black}
\setbeamercolor{block example body}{fg=black,bg=lightgray}
% Heading
\setbeamercolor{heading}{fg=black}
% Itemize
\setbeamercolor{item}{fg=labsixorange}
% Bibliography
\setbeamercolor{bibliography item}{fg=black}
\setbeamercolor{bibliography entry author}{fg=black}
\setbeamercolor{bibliography entry title}{fg=black}
\setbeamercolor{bibliography entry location}{fg=black}
\setbeamercolor{bibliography entry note}{fg=black}

57
beamercolorthememit.sty Normal file
View File

@ -0,0 +1,57 @@
% Gemini theme
% https://github.com/anishathalye/gemini
% ====================
% Definitions
% ====================
% Colors from http://web.mit.edu/graphicidentity/colors.html
\definecolor{mitred}{cmyk}{0.24, 1.0, 0.78, 0.17}
\definecolor{mitdarkgray}{cmyk}{0.48, 0.39, 0.39, 0.04}
\definecolor{mitlightgray}{cmyk}{0.24, 0.20, 0.20, 0.0}
% Extra colors
\definecolor{lightgray}{RGB}{240, 240, 240}
\definecolor{lightorange}{RGB}{255, 245, 242}
% ====================
% Theme
% ====================
% Basic colors
\setbeamercolor{palette primary}{fg=black,bg=white}
\setbeamercolor{palette secondary}{fg=black,bg=white}
\setbeamercolor{palette tertiary}{bg=black,fg=white}
\setbeamercolor{palette quaternary}{fg=black,bg=white}
\setbeamercolor{structure}{fg=mitred}
% Headline
\setbeamercolor{headline}{fg=black,bg=lightgray}
% Block
\setbeamercolor{block title}{fg=mitred,bg=white}
\setbeamercolor{block separator}{bg=black}
\setbeamercolor{block body}{fg=black,bg=white}
% Alert Block
\setbeamercolor{block alerted title}{fg=mitred,bg=lightorange}
\setbeamercolor{block alerted separator}{bg=black}
\setbeamercolor{block alerted body}{fg=black,bg=lightorange}
% Example Block
\setbeamercolor{block example title}{fg=mitred,bg=lightgray}
\setbeamercolor{block example separator}{bg=black}
\setbeamercolor{block example body}{fg=black,bg=lightgray}
% Heading
\setbeamercolor{heading}{fg=black}
% Itemize
\setbeamercolor{item}{fg=mitred}
% Bibliography
\setbeamercolor{bibliography item}{fg=black}
\setbeamercolor{bibliography entry author}{fg=black}
\setbeamercolor{bibliography entry title}{fg=black}
\setbeamercolor{bibliography entry location}{fg=black}
\setbeamercolor{bibliography entry note}{fg=black}

258
beamerthemegemini.sty Normal file
View File

@ -0,0 +1,258 @@
% Gemini theme
% https://github.com/anishathalye/gemini
% ====================
% Dependencies
% ====================
\RequirePackage{raleway}
\RequirePackage{exscale}
\RequirePackage{ragged2e}
\RequirePackage{changepage}
\RequirePackage{fontspec}
\RequirePackage{calc}
% ====================
% Fonts
% ====================
\newfontfamily\Raleway[Ligatures=TeX]{Raleway}
\newfontfamily\Lato[Ligatures=TeX]{Lato}
\usefonttheme{professionalfonts}
\setsansfont{Lato}[
UprightFont=*-Light,
ItalicFont=*-LightItalic,
BoldFont=*-Regular,
BoldItalicFont=*-Italic
]
\setbeamerfont{headline}{family=\Raleway}
\setbeamerfont{headline title}{size=\Huge,series=\bfseries}
\setbeamerfont{headline author}{size=\Large}
\setbeamerfont{headline institute}{size=\normalsize}
\setbeamerfont{block title}{family=\Raleway,size=\large,series=\bfseries}
\setbeamerfont{heading}{family=\Lato,series=\bfseries}
\setbeamerfont{caption}{size=\small}
\setbeamerfont{footline}{family=\Raleway,size=\normalsize}
% ====================
% Macros
% ====================
\newcommand{\samelineand}{\qquad}
% ====================
% Elements
% ====================
% List
\def\@listi{\leftmargin\leftmarginii
\topsep 1ex % spacing before
\parsep 0\p@ \@plus\p@
\itemsep 0.5ex} % spacing between
% Itemize
\setbeamertemplate{itemize item}{\raise0.5ex \hbox{\vrule width 0.5ex height 0.5ex}}
\setbeamertemplate{itemize subitem}{\raise0.3ex \hbox{\vrule width 0.5ex height 0.5ex}}
\setbeamertemplate{itemize subsubitem}{\raise0.2ex \hbox{\vrule width 0.5ex height 0.5ex}}
% Enumerate
\setbeamertemplate{enumerate item}{\insertenumlabel.}
\setbeamertemplate{enumerate subitem}{\insertsubenumlabel.}
\setbeamertemplate{enumerate subsubitem}{\insertsubsubenumlabel.}
% Equation
\setlength\belowdisplayshortskip{2ex}
% Caption
\setbeamertemplate{caption}[numbered]
\setbeamertemplate{caption label separator}[period]
\setlength{\abovecaptionskip}{2ex}
\setlength{\belowcaptionskip}{1ex}
% Bibliography
\setbeamertemplate{bibliography item}[text]
% Navigation
\beamertemplatenavigationsymbolsempty
% ====================
% Components
% ====================
% Heading
\newcommand\heading[1]
{%
\par\bigskip
{\usebeamerfont{heading}\usebeamercolor[fg]{heading}#1}\par\smallskip
}
% logo
\newlength{\logoleftwidth}
\setlength{\logoleftwidth}{0cm}
\newlength{\logorightwidth}
\setlength{\logorightwidth}{0cm}
\newlength{\maxlogowidth} % space on both sides set to maxlogowidth to keep title centered
\setlength{\maxlogowidth}{0cm}
\newcommand{\logoright}[1]{
\newcommand{\insertlogoright}{#1}
\settowidth{\logorightwidth}{\insertlogoright}
\addtolength{\logorightwidth}{10ex}
\setlength{\maxlogowidth}{\maxof{\logoleftwidth}{\logorightwidth}}
}
\newcommand{\logoleft}[1]{
\newcommand{\insertlogoleft}{#1}
\settowidth{\logoleftwidth}{\insertlogoleft}
\addtolength{\logoleftwidth}{10ex}
\setlength{\maxlogowidth}{\maxof{\logoleftwidth}{\logorightwidth}}
}
% Headline
\setbeamertemplate{headline}
{
\begin{beamercolorbox}{headline}
\begin{columns}
\begin{column}{\maxlogowidth}
\vskip5ex
\ifdefined\insertlogoleft
\vspace*{\fill}
\hspace{10ex}
\raggedright
\insertlogoleft
\vspace*{\fill}
\else\fi
\end{column}
\begin{column}{\dimexpr\paperwidth-\maxlogowidth-\maxlogowidth}
\usebeamerfont{headline}
\vskip3ex
\centering
\ifx \inserttitle \empty \else
{\usebeamerfont{headline title}\usebeamercolor[fg]{headline title}\inserttitle\\[0.5ex]}
\fi
\ifx \beamer@shortauthor \empty \else
{\usebeamerfont{headline author}\usebeamercolor[fg]{headline author}\insertauthor\\[1ex]}
\fi
\ifx \insertinstitute \empty \else
{\usebeamerfont{headline institute}\usebeamercolor[fg]{headline institute}\insertinstitute\\[1ex]}
\fi
\end{column}
\begin{column}{\maxlogowidth}
\vskip5ex
\ifdefined\insertlogoright
\vspace*{\fill}
\raggedleft
\insertlogoright
\hspace{10ex}
\vspace*{\fill}
\else\fi
\end{column}
\end{columns}
\vspace{5ex}
\ifbeamercolorempty[bg]{headline rule}{}{
\begin{beamercolorbox}[wd=\paperwidth,colsep=0.5ex]{headline rule}\end{beamercolorbox}
}
\end{beamercolorbox}
}
% Block
\setbeamertemplate{block begin}
{
\begin{beamercolorbox}[colsep*=0ex,dp=2ex,center]{block title}
\vskip0pt
\usebeamerfont{block title}\insertblocktitle
\vskip-1.25ex
\begin{beamercolorbox}[colsep=0.025ex]{block separator}\end{beamercolorbox}
\end{beamercolorbox}
{\parskip0pt\par}
\usebeamerfont{block body}
\vskip-0.5ex
\begin{beamercolorbox}[colsep*=0ex]{block body}
\justifying
\setlength{\parskip}{1ex}
\vskip-2ex
}
\setbeamertemplate{block end}
{
\end{beamercolorbox}
\vskip0pt
\vspace*{2ex}
}
% Alert Block
\setbeamertemplate{block alerted begin}
{
\begin{beamercolorbox}[colsep*=0ex,dp=2ex,center]{block alerted title}
\vskip0pt
\usebeamerfont{block title}\insertblocktitle
\vskip-1.25ex
\begin{beamercolorbox}[colsep=0.025ex]{block alerted separator}\end{beamercolorbox}
\end{beamercolorbox}
{\parskip0pt\par}
\usebeamerfont{block body}
\vskip-0.5ex
\begin{beamercolorbox}[colsep*=0ex]{block alerted body}
\justifying
\begin{adjustwidth}{1ex}{1ex}
\setlength{\parskip}{1ex}
\vskip-2ex
}
\setbeamertemplate{block alerted end}
{
\end{adjustwidth}
\vskip1ex
\end{beamercolorbox}
\vskip0pt
\vspace*{2ex}
}
% Example Block
\setbeamertemplate{block example begin}
{
\begin{beamercolorbox}[colsep*=0ex,dp=2ex,center]{block example title}
\vskip0pt
\usebeamerfont{block title}\insertblocktitle
\vskip-1.25ex
\begin{beamercolorbox}[colsep=0.025ex]{block example separator}\end{beamercolorbox}
\end{beamercolorbox}
{\parskip0pt\par}
\usebeamerfont{block body}
\vskip-0.5ex
\begin{beamercolorbox}[colsep*=0ex]{block example body}
\justifying
\begin{adjustwidth}{1ex}{1ex}
\setlength{\parskip}{1ex}
\vskip-2ex
}
\setbeamertemplate{block example end}
{
\end{adjustwidth}
\vskip1ex
\end{beamercolorbox}
\vskip0pt
\vspace*{2ex}
}
% Footer
\newcommand{\footercontent}[1]{\newcommand{\insertfootercontent}{#1}}
\setbeamertemplate{footline}{
\ifdefined\insertfootercontent
\begin{beamercolorbox}[vmode]{headline}
\ifbeamercolorempty[bg]{headline rule}{}{
\begin{beamercolorbox}[wd=\paperwidth,colsep=0.25ex]{headline rule}\end{beamercolorbox}
}
\vspace{1.5ex}
\hspace{\sepwidth}
\usebeamerfont{footline}
\centering
\insertfootercontent
\hspace{\sepwidth}
\vspace{1.5ex}
\end{beamercolorbox}
\else\fi
}

387
eesws_poster.tex Normal file
View File

@ -0,0 +1,387 @@
\documentclass[final]{beamer}
%% Possible paper sizes: a0, a0b, a1, a2, a3, a4.
%% Possible orientations: portrait, landscape
%% Font sizes can be changed using the scale option.
\usepackage[size=a0,orientation=portrait,scale=1.2]{beamerposter}
\usepackage[backend=biber,style=numeric,sorting=none]{biblatex}
\addbibresource{HKvsLieb.bib}
\usepackage{mathtools}
\newcommand{\red}[1]{\textcolor{red}{#1}}
\newcommand{\blue}[1]{\textcolor{blue}{#1}}
\newcommand{\green}[1]{\textcolor{green}{#1}}
\newcommand{\purple}[1]{\textcolor{purple}{#1}}
\newcommand{\hH}{\Hat{H}}
\newcommand{\hT}{\Hat{T}}
\newcommand{\hV}{\Hat{V}}
\newcommand{\hn}{\Hat{n}}
\newcommand{\cre}[1]{a_{#1}^\dagger}
\newcommand{\ani}[1]{a_{#1}}
\newcommand{\br}{\boldsymbol{r}}
\newcommand{\up}{\uparrow}
\newcommand{\dw}{\downarrow}
\newcommand{\Dv}{\Delta v}
\newcommand{\Dn}{\Delta n}
\newcommand{\ie}{\textit{i.e.}\xspace}
\AtEveryBibitem{%
\ifentrytype{article}{
\clearfield{url}%
\clearfield{urlyear}%
\clearfield{doi}%
\clearfield{issn}%
\clearfield{month}%
\clearfield{day}%
\clearfield{title}%
}{}
}
\DeclareFieldFormat[article]{pages}{#1}
\renewbibmacro{in:}{%
\ifentrytype{article}{}{\printtext{\bibstring{in}\intitlepunct}}}
\usetheme{gemini}
\usecolortheme{gemini}
\useinnertheme{rectangles}
% ====================
% Packages
% ====================
\usepackage[utf8]{inputenc}
\usepackage{graphicx,dcolumn,xcolor,microtype,multirow,amscd,amsmath,amssymb,amsfonts,physics,wrapfig,tikz,siunitx,bm}
\usepackage{booktabs}
\usepackage{tikz}
\usepackage{pgfplots}
\newfontfamily\qp{Times New Roman}[
% the font has no small caps, so we use another one for them
SmallCapsFont=TeX Gyre Termes,
SmallCapsFeatures={Letters=SmallCaps}
]
% ====================
% Lengths
% ====================
% If you have N columns, choose \sepwidth and \colwidth such that
% (N+1)*\sepwidth + N*\colwidth = \paperwidth
\newlength{\sepwidth}
\newlength{\colwidth}
\setlength{\sepwidth}{0.03\paperwidth}
\setlength{\colwidth}{0.45\paperwidth}
\newcommand{\separatorcolumn}{\begin{column}{\sepwidth}\end{column}}
% ====================
% Logo (optional)
% ====================
% LaTeX logo taken from https://commons.wikimedia.org/wiki/File:LaTeX_logo.svg
% use this to include logos on the left and/or right side of the header:
\logoright{\vspace{6cm} \includegraphics[width=10cm]{fig/Fermi.jpg}}
\logoleft{\vspace{-6cm} \includegraphics[width=10cm]{fig/ERC.jpg}}% \hspace{1cm} \includegraphics[height=6cm]{fig/CNRS.png} }
\addtobeamertemplate{headline}{}
{
\begin{tikzpicture}[remember picture,overlay]
\node [shift={(7.5 cm,-3.5cm)}] at (current page.north west) {\includegraphics[height=6cm]{fig/CNRS.png}};
\node [shift={(-7.25 cm,-4.5cm)}] at (current page.north east) {\includegraphics[width=10cm]{fig/LCPQ.jpg}};
\end{tikzpicture}
}
% ====================
% Footer (optional)
% ====================
\footercontent{
\href{mailto:sgiarrusso@irsamc.ups-tlse.fr}{\texttt{sgiarrusso@irsamc.ups-tlse.fr}}
\hfill
Sara Giarrusso and Pierre-Fran\c cois Loos, arXiv preprint arXiv:2303.15084
\hfill
\href{mailto:loos@irsamc.ups-tlse.fr}{\texttt{loos@irsamc.ups-tlse.fr}
}
}
% (can be left out to remove footer)
% ====================
% My own customization
% - BibLaTeX
% - Boxes with tcolorbox
% - User-defined commands
% ====================
%\input{custom-defs.tex}
%% Reference Sources
%\addbibresource{refs.bib}
%\renewcommand{\pgfuseimage}[1]{\includegraphics[scale=2.0]{#1}}
\newcommand{\LCPQ}{Laboratoire de Chimie et Physique Quantiques (UMR 5626), Universit\'e de Toulouse, CNRS, UPS, France}
\title{Exact Excited-State Functionals of the Asymmetric Hubbard Dimer}
\author{\underline{Sara Giarrusso},\inst{1}, Pierre-Fran\c cois Loos,\inst{1}}
\institute[shortinst]{\inst{1} \LCPQ}
\begin{document}
\begin{frame}[t]
%%%%%%%%%%%%%%%%
%%% Abstract %%%
%%%%%%%%%%%%%%%%
\begin{alertblock}{Abstract}
We derive, for the case of the asymmetric Hubbard dimer at half-filling, the exact functional associated with each singlet ground and excited state, using both Levy's constrained search and Lieb's convex formulation.
While the ground-state functional is, as commonly known, a convex function with respect to the density (or, more precisely, the site occupation), the functional associated with the (highest) doubly-excited state is found to be concave.
Also, we find that, because the density of the first excited state is non-invertible, its ``functional'' is a partial, multi-valued function composed of one concave and one convex branch that correspond to two separate sets of values of the external potential.
These findings offer insight into the challenges of developing state-specific excited-state density functionals for general applications in electronic structure theory.
\end{alertblock}
%%%%%%%%%%%%%%%%
\vspace{-1.3cm}
\begin{columns}[t]
\separatorcolumn
\begin{column}{\colwidth}
%\vspace{-2cm}
%%%%%%%%%%%%%%%%%%%%%%
\begin{block}{Theoretical background}
The variational principle can be reformulated in terms of the Hohenberg-Kohn functional as
\begin{equation}
\label{eq:HKvar}
E_0[v] = \min_{\rho}\qty{ F[\rho] + \int v(\br) \rho(\br) d\br } \Leftrightarrow \fdv{F[\rho(\br)]}{\rho(\br)} = - v(\br)
\end{equation}
$ F[\rho]$ is the ``Fenchel conjugate" of $E_0[v]$ and can be obtained from the Lieb variational principle (or convex formulation) as:
\begin{equation}
\label{eq:Lvar}
F[\rho] = \max_{v}\qty{ E[v] - \int v(\br) \rho(\br) d\br } \Leftrightarrow \fdv{E[v(\br)]}{v(\br)} = \rho(\br)
\end{equation}
Levy's constrained search requires $\rho$ to be only $N$-representable rather than $v$-representable, defining the Levy functional as
\begin{equation}
\label{eq:FLL}
F[\rho]
= \min_{\Psi \leadsto \rho} \mel{\Psi}{\hT + \hV_{ee}}{\Psi}
\end{equation}
\end{block}
%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%
%\vspace{-1.cm}
\begin{block}{The model}
The Hamiltonian of the asymmetric Hubbard dimer is
\begin{equation}
\hH =
- t \sum_{\sigma=\up,\dw} \qty( \cre{0\sigma} \ani{1\sigma} + \text{h.c.} )
+ U \sum_{i=0}^{1} \hat{n}_{i\up} \hat{n}_{i\dw}
+ \Dv \frac{\hn_{1} - \hn_{0}}{2}
\end{equation}
A generic singlet wave function can be written as
\begin{equation}
\ket{\Psi} = x \ket{0_\up0_\dw} + y \frac{\ket{0_\up1_\dw} - \ket{0_\dw1_\up}}{\sqrt{2}} + z \ket{1_\up1_\dw}
\end{equation}
with $-1 \le x,y,z \le 1$ and the normalization condition
\begin{equation}
\label{eq:normalization}
x^2 + y^2 + z^2 = 1
\end{equation}
\end{block}
%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%
% \vspace{-0.5cm}
\begin{block}{Ground and excited-state energies and densities}
The total energy, $E$, is given by the sum of
\begin{subequations}
\begin{align}
\label{eq:T}
&T = - 2\sqrt{2} t y \qty(x + z)
\\
\label{eq:Vee}
&V_{ee} = U \qty(x^2 + z^2)
\\
\label{eq:V}
&V = \rho \cdot \Dv \quad \text{with} \quad \rho=\mel{\Psi}{\frac{\hn_{1} - \hn_{0}}{2}}{\Psi} = (z^2 - x^2)
\end{align}
\end{subequations}
\includegraphics[scale=1.7]{fig/fig1}
\begin{columns}[T]
\begin{column}{.45\textwidth}
\includegraphics[scale=1.4]{fig/fig2}
\end{column}
\begin{column}{.45\textwidth}
In agreement with Eq.~\eqref{eq:Lvar}, one finds
\begin{equation}
\dv{E_0(\Dv)}{\Dv} =2\, \rho_0(\Dv)
\end{equation}
However, the same holds for the excited states
\begin{subequations}
\begin{align}
& \dv{E_1(\Dv)}{\Dv} =2\, \rho_1(\Dv)\\
& \dv{E_2(\Dv)}{\Dv} =2\, \rho_2(\Dv)
\end{align}
\end{subequations}
\end{column}
\begin{column}{.1\textwidth}
\end{column}
\end{columns}
\end{block}
%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%
%\vspace{-0.5cm}
\begin{block}{Levy's constrained search}
\begin{columns}[T]
\begin{column}{.35\textwidth}
\hspace{-3.5cm}
$\phantom{0\,\,}$\includegraphics[scale=1.2]{fig/fig5}
\end{column}
\begin{column}{.5\textwidth}
\vspace{1cm}
Substituting $x$ and $z$, we obtain the four-branch function
\hspace{-3cm}
{\small{\begin{align}
\label{eq:fpm}
f_{\pm\pm}(\rho,y)
= & - 2 t y \qty (\pm\sqrt{1 - y^2 - \rho}
\pm \sqrt{1 - y^2 + \rho}) \notag
\\
&+ U \qty(1 - y^2)
\end{align}} }
Rather than only minimizing $f_{\pm\pm}(\rho,y) $
for a given $\rho$, we seek \textit{all} its stationary points with respect to $y$:
\begin{equation}
\pdv{f_{\pm\pm}(\rho,y)}{y} = 0
\end{equation}
\end{column}
\begin{column}{.1\textwidth}
\end{column}
\end{columns}
\end{block}
%%%%%%%%%%%%%%%%%%%%%%
\end{column}
\separatorcolumn
\begin{column}{\colwidth}
\vspace{3cm}
%
%%%%%%%%%%%%%%%%%%%%%%
% \begin{block}{}
\includegraphics[scale=1.35]{fig/fig3}
$f_{--}(\rho,y)$ (red) and $f_{++}(\rho,y)$ (green) have each one stationary point for $y \geq 0$, while $f_{+-}(\rho,y)$ (yellow) has two stationary points that disappear for $\rho > \rho_c$.
% \end{block}
\vspace{0.5cm}
%%%%%%%%%%%%%%%%%%%%%%
\begin{block}{Ground and excited-state ``universal" function(al)s}
%
\begin{columns}[T]
\begin{column}{.45\textwidth}
\includegraphics[scale=1.5]{fig/fig4} \\
\includegraphics[scale=1.5]{fig/Vvsrho}
\end{column}
\begin{column}{.45\textwidth}
\vspace{0.5cm}
\begin{subequations}
\begin{align}
& F_0(\rho)=f_{++}(\rho,y_0)\\
& F_2(\rho)=f_{--}(\rho,y_2)\\
& \begin{rcases} F_1^{\cup}(\rho) = f_{+-}(\rho,y_1^{\cup}))\\
F_1^{\cap}(\rho) = f_{+-}(\rho,y_1^{\cap}
\end{rcases} \quad \rho < \rho_\text{c}
\end{align}
\end{subequations}
\vspace{1.5cm}
%\dv{F_2(\rho)}{\rho} = -\Dv_2 (\rho)
In agreement with Eq.~\eqref{eq:HKvar} and beyond the ground state, one finds
\begin{subequations}
\begin{align}
& \dv{F_0(\rho)}{\rho} = -\Dv_0 (\rho)\\
& \dv{F_2(\rho)}{\rho} = -\Dv_2 (\rho)\\
& \begin{rcases} \dv{F_1^{\cup}(\rho)}{\rho} = - \Dv_1^{\cup}(\rho)\\
\dv{F_1^{\cap}(\rho)}{\rho} = -\Dv_1^{\cap}(\rho) \end{rcases} \quad \rho < \rho_\text{c}
\end{align}
\end{subequations}
\end{column}
\end{columns}
\end{block}
%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%
\begin{block}{Lieb's convex formulation}
\vspace{0.5cm}
\begin{columns}
\begin{column}{.45\textwidth}
\includegraphics[scale=1.5]{fig/fig6}
\end{column}
\begin{column}{.5\textwidth}
\begin{equation}
f_{n}(\rho,\Dv) = E_n - \Dv \rho
\end{equation}
Rather than only maximizing $ f_{n}(\rho,\Dv) $ for a given $\rho$, we seek \textit{all} its stationary points with respect to $\Dv$ for each $n$ value,
\begin{equation}
\pdv{f_{n}(\rho,\Dv)}{\Dv} = 0
\end{equation}
\end{column}
\end{columns}
\end{block}
\vspace{-1.3cm}
%%%%%%%%%%%%%%%%%%%%%%
\begin{block}{Conclusions}
While the ground-state functional is well-known to be a convex function with respect to the difference in site occupations, the functional associated with the highest doubly-excited state is found to be concave.
Additionally, and more importantly, we discovered that the ``functional'' for the first excited state is a partial, multi-valued function of the density that is constructed from one concave and one convex branch associated with two separate sets of values of the external potential.
Finally, we find that Levy's constrained search and Lieb's convex formulation are entirely consistent for all the states of the model, producing the same landscape of state-specific functionals.
\end{block}
%%%%%%%%%%%%%%%%%%%%%%%
\vspace{-0.4cm}
%%% Acknowledgement %%%
%%%%%%%%%%%%%%%%%%%%%%%
\begin{block}{Acknowledgement}
\textit{This project has received funding from the European Research Council (ERC)
under the European Union's Horizon 2020 research and innovation programme,
grant agreement No.~863481.}
\end{block}
%%%%%%%%%%%%%%%%%%%%%%%
\vspace{-1.cm}
%%%%%%%%%%%%%%%%%%
%%% References %%%
%%%%%%%%%%%%%%%%%%
\begin{block}{References}
%\printbibliography
{\footnotesize{
\parbox[b]{\hsize}{[1] P. Hohenberg, and W. Kohn, \textit{Inhomogeneous electron gas}, Phys. rev. 136.3B (1964): B864.}\\
\parbox[b]{\hsize}{[2] M. Levy, \textit{Universal variational functionals of electron densities, first-order density matrices, and natural spin-orbitals and solution of the v-representability problem} Proc. Nat. Ac. Sci 76.12 (1979): 6062-6065.}\\
\parbox[b]{\hsize}{[3] E. H. Lieb, \textit{Density functionals for Coulomb systems} Int. J. Quantum Chem. \textbf{24}, 243 (1983).}\\
\parbox[b]{\hsize}{[4] D. J. Carrascal, J. Ferrer, J. C. Smith, and K. Burke, \textit{The Hubbard dimer: a density functional case study of a many-body problem}, J.Phys. Condens. Matter \textbf{27}, 393001 (2015).}\\
\parbox[b]{\hsize}{[5] J. P. Perdew, and M. Levy, \textit{Extrema of the density functional for the energy: Excited states from the ground-state theory}, Phys. Rev. B 31.10 (1985): 6264. \\
}
}}
\end{block}
%%%%%%%%%%%%%%%%%%
\end{column}
\separatorcolumn
\end{columns}
\end{frame}
\end{document}

BIN
fig/Vvsrho.pdf Normal file

Binary file not shown.

BIN
fig/fig1.pdf Normal file

Binary file not shown.

BIN
fig/fig2.pdf Normal file

Binary file not shown.

BIN
fig/fig3.pdf Normal file

Binary file not shown.

BIN
fig/fig4.pdf Normal file

Binary file not shown.

BIN
fig/fig5.pdf Normal file

Binary file not shown.

BIN
fig/fig6.pdf Normal file

Binary file not shown.