Читать книгу Quantum Mechanics, Volume 3 - Claude Cohen-Tannoudji - Страница 26

Creation and annihilation operators have very simple commutation (for the bosons) and anticommutation (for the fermions) properties, which make them easy tools for taking into account the symmetrization or antisymmetrization of the state vectors.

To simplify the notation, each time the equations refer to a single basis of individual states |ui〉, we shall write ai instead of aui. If, however, it can lead to ambiguity, we will return to the full notation.