S1 Supporting Information Current-Driven Hydrogen Desorption from Graphene: Experiment and Theory Li Gao, †,‡ Partha Pratim Pal, § Tamar Seideman, § Nathan P. Guisinger, ‡ and Jeffrey R. Guest *,‡ † Department of Physics and Astronomy, California State University, Northridge, California 91330, United States ‡ Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439, United States § Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States Supplementary Figure S1: STM image (40 nm × 40 nm, 2 V, 5 pA) of the graphene/SiC(0001) surface after one 5 nm wide line of pristine graphene was written through hydrogen desorption. The hydrogen desorption experiment was performed at a sample bias of 3.5 V, a current of 2 nA, and a scan speed of 1 nm/s. Supplementary Note 1: Preparation and hydrogen passivation of the graphene/SiC(0001) surface.