This Hamiltonian is exactly similar to that of a two state system with unperturbed energies ℏ ℏ 2 Δ Δ ω ω and − − ℏ ℏ 2 Δ Δ ω ω with a perturbation expressed by ℏ ℏ 2 ( 0 − − ω ω 1 − − ω ω 1 0 ) ; According to Rabi oscillation, starting with [ 1 0 ] state, a dipole in parallel to B 0 with energy − − ℏ ℏ 2 ω ω 0 , the probability that it will transit to [ 0 1 ] state (i.e. it will flip) is