= Phase-dependent cat-state quadrature variance
{title2=$\operatorname{Var}X_2=\frac14-\frac{\alpha^2s(\cos\phi+s)}{(1+s\cos\phi)^2}$}
For real $\alpha$, put $s=e^{-2\alpha^2}$ in $N(|\alpha\rangle+e^{i\phi}|-\alpha\rangle)$. Its mean second quadrature is $-\alpha s\sin\phi/(1+s\cos\phi)$, which is generally nonzero. Subtracting its square from the second moment gives the displayed <variance> and squeezing precisely when $\cos\phi>-s$, for nonzero finite amplitude. A useful counterexample to confusing moment and <variance> is $\phi=\pi/2$.
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