Fig. 2: Lamella under various biasing conditions.

a–c The I-V responses of the same lamella (L1) upon three bias voltage sweeps, as indicated at the top. d–f HAADF images and the corresponding composite maps of Pd, S, and Ag based on EDXS elemental mapping acquired directly after (a–c), where L1 was left at high resistance state (HRS) or low resistance state (LRS). At the bottom are enlarged maps from the regions outlined by the solid rectangles. The upper left insets in (e and f) are enlarged images from the regions outlined by the dotted rectangles with adjusted contrast limit. g HAADF and Ag intensity profiles along the two dotted lines in (e and f). Two pairs of gray lines mark the same positions. h Enlarged images from the dashed rectangles in (d–f). Both the isolated Ag particle (left) and the Ag electrode (right) are outlined, and their shapes are compared. A thick Ag filament (~12 \(\times\)135 nm) fills the space between the two MoS₂ bundles.