Fig. 3: Conduction response of the 180°-DWs at cryogenic temperatures.

a–e Topography, PFM and cAFM images of poled regions at 4 K. f–j Same images as in a–e at 42 K. In the PFM-phase images c and h the clear 180° contrast between pristine (yellow) and poled (purple) domains is visible. The 180°-DWs (black square outlines in b and g), show strong conductivity as confirmed by the cAFM images. This conduction is detectable under varying imaging parameters like scanning angle (d–e) or voltage bias (i–j) both at 4 K and 42 K. In all cAFM images, in addition to 180°-DWs, an enhanced conduction of the 90°-DWs inside the poled regions is observed. k Shows single-spot I–V characteristics at 42 K of a pristine 90°-DW outside the poled region (black), the enhanced 90°-DW conduction inside (purple) and the strong 180°-DW response (orange). The insert indicates the positions where the I–V curves where taken with the tip as a top electrode. l, m An averaged cross-section profile at 4 K and 42 K collected on the marked areas in e and j show similar maximum current around 800 pA for both temperatures.