Landmark modeling study reveals how ferroelectric computer memory works

a) A snapshot of the polarization from an molecular dynamics simulation of PbTiO3 at 220 K and 0.5 MV cm21. The local polarization vectors are shown by the red and blue arrows. The two domain walls are outlined with red lines. b) A critical nucleus on the domain wall on the y–z plane. The green solid line shows the boundary of the critical nucleus. c) The fraction of the simulations exhibiting no nucleation by time t. The exponent of the fit function corresponds to the nucleation rate J. d) Size dependence of the nucleation rates on the (100) 180u domain wall. Credit: Nature and the University of Pennsyvlania