Extended Data Fig. 1: Electron spectrometry of the superlattice.

a, Schematic of the electron microscopy pixel array detector (EMPAD) placed in the diffraction plane to record the full angular scattering distribution from an electron beam focused onto a sample. b, ADF image of the (PbTiO3)12/(SrTiO3)12 superlattice along the [010]pc zone axis. c, d, CBED pattern from the PbTiO3 layer (c) and from the SrTiO3 layer (d).