Introduction Motivation Polarization rotation first-principle calculation T [0011 0 [101 6 5 PZN-PT PZN 令 M 4 3 2 b 1 g 0.00.51.01.52.02.53.0 Path distance H.Fu,R.E.Cohen,Nature 403,281(2000) Introduction & Motivation Polarization rotation  first-principle calculation PZN PZN-PT H.Fu, R.E.Cohen, Nature 403, 281 (2000)