Fig. 5: Measurement of handedness of the chiral polar textures using 4D-STEM.

A A representative experimental diffraction pattern acquired at 373 K (from the meron square lattice phase), oriented ~6.2° away from [001] zone axis, and tilted along one of the mirror planes. B Map of normalized intensity difference between (771) and (\(\bar{7}71\)) reflections reconstructed from the 4D-STEM dataset—i.e. one diffraction pattern is recorded at each spatial pixel in B. The positive (negative) regions indicate the polar textures having left-handed (right-handed) chirality. C Intensity line profiles of HOLZ reflections from diffraction patterns taken in from the selected regions #1, #2 labeled in B, displaying the intensity difference between two pairs of reflections: (671) and (\(\bar{6}71\)), (771) and (\(\bar{7}71\)). The colored labels in B indicates the region from which the diffraction patterns of C were extracted. The colored diffraction intensity profiles with markers show experimental data, whereas the simulation of a right-handed meron is shown in dashed gray line at the bottom. The dashed yellow box in A shows the region of diffraction space integrated to produce the HOLZ line profiles in C.