= Pairing Majorana operators into a fermionic mode
{title2=$f=(\gamma_a+i\gamma_b)/2,\quad f^\dagger f=(1+i\gamma_a\gamma_b)/2$}
Two distinct <Majorana fermion operators> with $\{\gamma_i,\gamma_j\}=2\delta_{ij}$ define the displayed <fermionic annihilation operator>. Direct multiplication gives $f^2=0$ and $\{f,f^\dagger\}=1$. Its <number operator> is a <projection operator> with <eigenvalues> zero and one. An individual Hermitian Majorana operator has $\gamma_i^\dagger\gamma_i=\gamma_i^2=1$, so that expression is not a nontrivial occupation observable. The occupation belongs to a chosen pair. A quadratic coupling $iJ\gamma_a\gamma_b=J(2f^\dagger f-1)$ splits the pair's two occupations by $2|J|$.
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