Construction of atomic-scale logic gates on a surface of hydrogen passivated germanium

We describe a complete protocol for atomically precise dangling bond (DB) logic gate construction on a hydrogenated Ge(001):H surface. Starting from the preparation of the reconstructed Ge(001) surface followed by its passivation with hydrogen atoms we end up with the platform for scanning tunneling microscopy (STM) atomic-scale lithography. Finally with the use of dimer-by-dimer STM tip-induced hydrogen desorption from the Ge(001) - (2 x 1):H surface the DB nanostructures of pre-designed form are fabricated. Furthermore, the STM tip manipulation provides the control over the buckling phase of a single DB dimer incorporated into the DB logic gate structure, which is of crucial importance for the final electronic properties of the system. Our results prove feasibility of DB atomic scale logic gate implementation on the passivated semiconductor surfaces.