Fig. 2
Kikuchi lines and atomic layer-by-layer variations of the mean inner potential. a Schematic of the formation of Kikuchi lines. G is the reciprocal vector of the lattice, P and D are the momentum vectors of the primary incident electron beam and the outgoing beam that satisfy the Bragg condition. The red dots and lines on the screen are the diffraction peaks and the Kikuchi lines, respectively. b A typical RHEED pattern taken along the SrTiO3 [110] direction, showing Kikuchi lines clearly. The dashed lines are fits to the Kikuchi lines using Eq. (1). c Periodic variation of the extracted mean inner potential. The error bars are the fitting error of the Kikuchi lines corresponding to G(224) and G(113) in each RHEED pattern using Eq. (15) in the Supplementary Note 6. d Position shift Ry of the Kikuchi lines and the small error bars indicate clear and reliable relative change of the mean inner potential during the growth (Supplementary Fig. 7 and Supplementary Note 7). The error bars are the fitting error of the Kikuchi lines using Guassian function
