(color online) (a) Overview STM image (V = −1.5 V, I = 150 pA) of 6-ED-ZGNRs fabricated on Au (111) surface with scale bar being 20 nm. Inset shows high-resolution STM image (V = 0.15 V, I = 2 pA), with scale bar being 1 nm;^[11] (b) four different spin configurations on edges; (c) DFT-based density of states at E = −0.10 eV (corresponding to the highest occupied state) and E = 0.15 eV (corresponding to the lowest unoccupied level);^[11] (d) spin-polarized charge density of 6-ED-ZGNR, with the spin-up and spin-down electron densities represented by the yellow and cyan colors, respectively.