\documentclass[]{standalone}
\usepackage[]{graphicx}
\usepackage[]{luatexja-preset}
\usepackage{amsmath,amssymb,amsfonts,bm,mathrsfs}
\usepackage{tikz}
\usepackage{pgfplots}
\pgfplotsset{compat=1.17}
\tikzset{>=latex}
\usetikzlibrary{arrows,arrows.meta}
\usepackage{steinmetz}
\newcommand*{\equal}{=}
\usepackage{tikz-3dplot}
\usepackage[european resistors]{circuitikz}
\usetikzlibrary{decorations.markings}
\tikzset{->-/.style={decoration={
markings,
mark=at position #1 with {\arrow{>}}},postaction={decorate}}}
\tikzset{-<-/.style={decoration={
markings,
mark=at position #1 with {\arrow{<}}},postaction={decorate}}}
\begin{document}
\begin{tikzpicture}
\begin{axis}[
width=5cm,
height=5cm,
%axis y line=middle, axis x line=middle,
hide axis,
scale only axis,
ticks=none,
xmin = -0.5, xmax = 2.5,
ymin = -0.5, ymax = 2.5,
xlabel={$\mathrm{Re}$},
ylabel={$\mathrm{Im}$},
]
\draw[->] (2,0) -- (-0.3,0) node[above] {$\mathrm{Im}$};
\draw[->] (0,-0.5) -- (0,1) node[left] {$\mathrm{Re}$};
\draw[very thick,red,->] (0,0) -- (0.0,0.9) node[right] {$E$};
\draw[very thick, ->] (0,0) node[circle, fill,inner sep=0pt, minimum size=3pt]{}-- (0.5,0.866) node[circle, fill,inner sep=0pt, minimum size=3pt]{} node[above, right] {$I_s$};
\draw[very thick, ->] (0,0) -- (1.8,0.65) node[above] {$I_{s=1}$};
\draw[] (0,0) --(0.6,1.04);
\draw[] (2,0) node[circle, fill,inner sep=0pt, minimum size=3pt]{} --(0,1.154);
\draw[] (0.5,0.866) node[above]{A};
\draw[] (2,0) node[below] {B};
\draw[] (0,0) node[below=5pt,left=-3pt] {O};
\draw[dotted] (2,0) arc(0:180:1);
\draw[] (1.7,0) arc(180:150:0.3) node[left=7pt,below=-6pt]{$\alpha_s$};
\draw[] (0,0.25) arc(-270:-300:0.25) node[fill=white,inner sep=1pt, opacity=.9,left=1pt,above=3pt] {$\alpha_s$};
\draw[] (0,0.5) arc(-270:-340:0.5) node[above=12pt,right=-10pt] {$\alpha_{s=1}$};
\draw[dashed,<->] (1.8,0) -- (1.8,0.65) node[midway, right]{\footnotesize{$r_1+r_2$}};
\draw[dashed,<->] (0,-0.1) -- (1.8,-0.1) node[midway, fill=white,inner sep=0pt]{\footnotesize{$x_1+x_2$}};
\end{axis}
\end{tikzpicture}
\end{document}