trying to add subcaption or subfloat with circuitikz or tabular but could not succeed

Question

I've been trying to add subcaption under the circuit drawing but could not succeed yet. I do not know how to add \subcaption or \subfloat. I only know how to do that with images but not with \circuitikz or \tabular

\documentclass[10pt,letterpaper,twocolumn,aps,pra, superscriptaddress,longbibliography]{revtex4-2}

\usepackage{xcolor}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{braket}
\usepackage{circuitikz}
\usepackage{tikz}
\usetikzlibrary{quantikz}
\usepackage[export]{adjustbox}
\usepackage{subcaption,graphicx}
\captionsetup{
  subrefformat=parens
}

\begin{document}

\begin{figure}[h]
\centering
\begin{circuitikz}[american,baseline=(current bounding box.center) ]
\draw 
(0,1) to [short, -*](0,1)
to [inductor](0,-1)
to [short, -*](0,-1);
\end{circuitikz}
\subcaptionbox{}[.4\linewidth][c]
\hfil  
\subcaptionbox{}[.4\linewidth][c]{
    \includegraphics[width=\linewidth]{Array-Falsecolour}}
\caption{The kinetic inductor a) A circuit diagram of an inductor. b) A fabricated JJ array with Manhattan-style.}
\label{array}
\end{figure}

\end{document}

My expectation is to have the subcaption 'a' under the inductor element, not in the middle of the whole figure.

Answer 1

You can use the circuitikz the same way you use \includegraphics inside the \subcaptionbox:

\documentclass[10pt,letterpaper,twocolumn,aps,pra, superscriptaddress,longbibliography]{revtex4-2}

\usepackage{xcolor}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{braket}
\usepackage{circuitikz}
\usepackage{tikz}
\usetikzlibrary{quantikz}
\usepackage[export]{adjustbox}
\usepackage{subcaption,graphicx}
\captionsetup{
  subrefformat=parens
}

\begin{document}

\begin{figure}[h]
\centering
\subcaptionbox{}[.4\linewidth][c]{%
\begin{circuitikz}[american,baseline=(current bounding box.center) ]
\draw 
(0,1) to [short, -*](0,1)
to [inductor](0,-1)
to [short, -*](0,-1);
\end{circuitikz}%
}
\hfil  
\subcaptionbox{}[.4\linewidth][c]{%
    \includegraphics[width=\linewidth]{example-image-duck}%
}
\caption{The kinetic inductor a) A circuit diagram of an inductor. b) A fabricated JJ array with Manhattan-style.}
\label{array}
\end{figure}

\end{document}