Recent content by junjunxu

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    What's the Normal Order of A + B?

    Homework Statement Hi, guys, I just wondering what's the normal order of A +B Homework Equations if N[A+B]=N[A]+N[B] then I have N[aa^{\dagger}]=N[1-a^{\dagger}a]=1-a^{\dagger}a however we know that N[aa^{\dagger}]=-a^{\dagger}a] what's wrong? The Attempt at a Solution...