So when ω ω = ω ω 0 , a high precession amplitude allows the magnetic moment to be completely flipped. Classical and quantum mechanical predictions correspond well, which can be viewed as an example of the Bohr Correspondence principle, which states that quantum mechanical phenomena, when predicted in classical regime, should match the classical result. The origin of this correspondence is that the evolution of the expected value of magnetic moment is identical to that obtained by classical reasoning. The expectation value of the magnetic moment is ⟨ ⟨ m ⟩ ⟩ = γ γ ⟨ ⟨ S ⟩ ⟩ . The time evolution of ⟨ ⟨ m ⟩ ⟩ is given by