Why does the expectation values of some operators, such as 'number' operator ##a^\dagger a## and atomic population operator ##\sigma^\dagger\sigma##, are always nonnegative? Can we prove this from a mathematical point? For example, are these operators positive semidefinite?
Why does expectation values are always nonnegative?
Why does expectation values are always nonnegative?
0 commentaires:
Enregistrer un commentaire