What is the physical interpretation of the operator
a_\alpha and what is the effect of
a_\alpha on a given state
|\alpha_1\alpha_2\dots\alpha_n\rangle_{\mathrm{AS}} ?
Consider the following matrix element
\begin{equation}
\langle\alpha_1\alpha_2 \dots \alpha_n|a_\alpha|\alpha_1'\alpha_2' \dots \alpha_m'\rangle \tag{11}
\end{equation}
where both sides are antisymmetric. We distinguish between two cases. The first (1) is when
\alpha \in \{\alpha_i\} . Using the Pauli principle of Eq.
(6) it follows
\begin{equation}
\langle\alpha_1\alpha_2 \dots \alpha_n|a_\alpha = 0 \tag{12}
\end{equation}
The second (2) case is when
\alpha \notin \{\alpha_i\} . It follows that an hermitian conjugation
\begin{equation}
\langle \alpha_1\alpha_2 \dots \alpha_n|a_\alpha = \langle\alpha\alpha_1\alpha_2 \dots \alpha_n| \tag{13}
\end{equation}