Tikz: Curved parallel arrow around a circle [duplicate]

I have a simple following code:

\begin{tikzpicture}
\draw[thick] (2,0) circle (1.5cm);
\end{tikzpicture}


I would like to create a curved parallel naming arrow around this circle as shown in the image.

\begin{tikzpicture}
\draw[-latex] (0.2,0) arc (180:120:1.8cm) node[near start,left] {$n$};
`