"Rotating wave approximation" Vab = A exp(i phi) -- arbitrary complex number Vba = conj(Vab) cb = -i/hbar Vba sin(omegar t) / (2 omegar) exp(i/2 (omega0 - omega) t) ca = -2 hbar / (i Vba exp(i (omega0 - omega) t)) d(cb,t) check(ca == (cos(omegar t) + i (omega0 - omega) / (2 omegar) sin(omegar t)) exp(-i/2 (omega0 - omega) t)) omegar = 1/2 sqrt((omega0 - omega)^2 + Vab Vba / hbar^2) "Verify equation (4)" check(d(ca,t) == -i / (2 hbar) Vab exp(i (omega - omega0) t) cb) "ok" "Verify equation (5)" check(d(cb,t) == -i / (2 hbar) Vba exp(i (omega0 - omega) t) ca) "ok" Run