Fig. 3: Topological transition as a function of the sizes of nanoislands.
From: Observation of multi-order polar radial vortices and their topological transition
a–b V-amp. and V-pha. images of the BFO film with the averaged size of nanoislands being 100 nm. c Phase spacing profile around one nanoisland in the inset of (b). d Reconstructed 3D polarization pattern of one-order radial vortex. The schematic at the bottom right corner showing the OOP polarization distribution around one nanoisland. e, f V-amp. and V-pha. images of the BFO film with the averaged size of nanoislands being 200 nm. g Phase spacing profile around one nanoisland in the inset of (f). h Reconstructed 3D polarization pattern of one-order radial vortex. The schematic at the bottom right corner showing the OOP polarization distribution around one nanoisland. i, j V-amp. and V-pha. images of the BFO film with the averaged size of nanoislands being 400 nm. k Phase spacing profile around one nanoisland in the inset of (j), l Reconstructed 3D polarization pattern of three-order radial vortex. The schematic at the bottom right corner showing the OOP polarization distribution around one nanoisland.
