Fig. 1.

Atomic resolution 4D STEM of pristine MoS₂ and WS₂. a Schematic illustration of the 4D STEM geometry used. b 4D STEM data plotted as montage of CBED patterns, showing variations as a function of probe position relative to Mo and 2S atom positions. Scale bar indicates 0.2 nm. c CBED pattern from the position marked with the white box 1 in b, and d CBED pattern from the position marked with the green box in b. e HAADF-STEM image of MoS₂ taken using the ADF detector. Scale bar indicates 0.2 nm. f DFT-calculated E_┴y field around MoS₂. g Experimental E_┴y field around MoS₂ measured from I_comy, normalized and scaled to the range matching the DFT values. h DFT-calculated E_┴x field around MoS₂. i Experimental E_┴x field around MoS₂ measured from I_comx, scaled to the range matching the DFT values. j Atomic model of MoS₂ in a tilted projection to show 2S column. k DFT calculated |E_┴| around MoS₂, according to the atomic model in (j). Scale bar indicates 0.2 nm. l Experimental |E_┴| around MoS₂ measured from the I_com, scaled to the range matching the DFT data. m Atomic model of WS₂ in a tilted projection to show 2S column. n DFT calculated |E_┴| around WS₂, according to the atomic model in m. Scale bar indicates 0.2 nm. o Experimental |E_┴| around WS₂ measured from I_com, scaled to the range matching the DFT data. Orange dots in e−n indicate S atoms position, cyan dots represent Mo and blue dots W. p 2D map of the E_┴ vector, from the I_com vector, in arrow representation (arrow size indicates the magnitude of vector) around the MoS₂ lattice. Scale bar indicates 0.1 nm. q Magnified view from the red dashed boxed area in p showing a high-resolution E_┴ vector plot around a single Mo atom and 2S column. Scale bar indicates 0.05 nm