Chiral Self-assembly Of 2,2’:6’,2"-terpyridine-4’-carboxylic Acid Molecules And Manipulation Of Single Ag Atom On HUCs Of Si(111)-7×7 Surface By Ag Cluster

The self-assembled supramolecular structures of 2,2’:6’,2’’-terpyridine-4’-carboxylic acid(Y)molecules on Cu(111)surfacehave been systematically studied by the combination of scanning tunneling microscopy(STM)and density function theory(DFT)calculations.After the annealing treatment,the as-deposited monolayer of 2,2’:6’,2’’-terpyridine-4’-carboxylic acid molecules was transferred into a large-area vortex-shaped chiral self-assembly.The Y molecule,bridging two nearest-neighbor Cu atoms,is stabilized by symmetric Cu-O bonds on the surface.It is found that chirality of these assembled structures is maintained and transferred from one vortex to the adjacent vortex in successive molecular domains within the same atomic terrace.Based on the fact that single Ag atom adsorbs on the faulted or unfaulted half-unit cells(HUCs)of the Si(111)-(7×7)reconstructed surface and such Ag atom constantly jumps among the equivalent positions within the HUCs at room temperature,mechanical gate manipulation protocol has been proposed to control the hopping of single Ag atom between the FHUC and the UHUC.Precise controlling on the hopping directions of Ag atom,long distance transfer of Ag atom and construction of Ag cluster with certain number have been successfully achieved by decreasing the hopping barrier due to the mechanical force applied by a scanning tunneling microscopy(STM)tip.Moreover,it is found that the intercell diffusion of Ag monomer can be effectively modified by the Ag cluster in the neighbor half cell.Based on such modification of Ag cluster on the diffusion of Ag monomer,for the first time,a quaternary logic dynamic storage device with the writing and reading functions of "0","1","2","3" has been constructedwith the configuration of AgN clusters and single Ag atoms on HUCs.