括弧の整列

Question

[こんにちは。1行目と 2 行目の2 つの左括弧を揃える方法はありますか?

\begin{align}
&\quad[v^{*}a^{-} +va^{\dagger}_{-k}]e^{+ik_{z}\centerdot z}=[u^{*}b^{-} +ub^{\dagger}_{-k}]e^{+ik_{z}\centerdot z} \nonumber \\ 
& \Rightarrow [\alpha u^{*}a^{-} +\beta u a^{-}+\alpha^{*}u a^{\dagger}_{-k}+\beta^{*} u^{*}a^{+}_{-k}]e^{+ik_{z}\centerdot z}=[u^{*}b^{-} +ub^{\dagger}_{-k}]e^{+ik_{z}\centerdot z} 
\end{align}

Answer 1

\documentclass{article}
\usepackage{amsmath}
\usepackage{amssymb}
\begin{document}
\begin{align}
    & [v^{*}a^{-} +va^{\dagger}_{-k}]e^{+ik_{z}\centerdot z}=[u^{*}b^{-} +ub^{\dagger}_{-k}]e^{+ik_{z}\centerdot z} \nonumber \\
    \Rightarrow & [\alpha u^{*}a^{-} +\beta u a^{-}+\alpha^{*}u a^{\dagger}_{-k}+\beta^{*} u^{*}a^{+}_{-k}]e^{+ik_{z}\centerdot z}=[u^{*}b^{-} +ub^{\dagger}_{-k}]e^{+ik_{z}\centerdot z}
\end{align}
\end{document}

結果：