Geometric phase is well defined for any sequence of pure states w1)v2)3)…vx) (Pancharatnam formula) y=arg{wwy2vy2y2).(v=)wxv ve W Using Pancharatnam formula we can easily calculate the geometric phase for each trajectory Wia wavo geodesic The area enclosed inside the trajectory geodesic joining final and initial states) Winw Wo… Wie way20 • Using Pancharatnam formula we can easily calculate the geometric phase for each trajectory: (The area enclosed inside the trajectory + geodesic joining final and initial states) 1 2 3 , , ,...     N          = arg ...  1 2 2 3 1 1 N N N −  • Geometric phase is well defined for any sequence of pure states (Pancharatnam formula):