title: Capturing the embryonic stages of self-assembly - design rules for molecular computation.
abstract: The drive towards organic computing is gaining momentum. Interestingly, the building blocks for such architectures is based on molecular ensembles extending from nucleic acids to synthetic molecules. Advancement in this direction requires devising precise nanoscopic experiments and model calculations to decipher the mechanisms governing the integration of a large number of molecules over time at room-temperature. Here, we report on ultrahigh-resolution scanning tunnelling microscopic measurements to register the motion of molecules in the absence of external stimulus in liquid medium. We observe the collective behavior of individual molecules within a swarm which constantly iterate their position to attain an energetically favourable site. Our approach provides a consistent pathway to register molecular self-assembly in sequential steps from visualising thermodynamically driven repair of defects up until the formation of a stable two-dimensional configuration. These elemental findings on molecular surface dynamics, self-repair and intermolecular kinetic pathways rationalised by atom-scale simulations can be explored for developing new models in algorithmic self-assembly to realisation of evolvable hardware.
authors.affiliation: IBM Research-Zurich, Säumerstrasse 4, CH- 8803, Rüschlikon, Switzerland.
authors.forename: Peter N
authors.initials: PN
authors.lastname: Nirmalraj
authors.affiliation: Materials and Surface Science Institute and Department of Physics and Energy, University of Limerick, Ireland.
authors.forename: Damien
authors.initials: D
authors.lastname: Thompson
authors.affiliation: IBM Research-Zurich, Säumerstrasse 4, CH- 8803, Rüschlikon, Switzerland.
authors.forename: Heike E
authors.initials: HE
authors.lastname: Riel
mesh_terms: D039301:Computers, Molecular; D037741:Fullerenes / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D016252:Microscopy, Scanning Tunneling; D013816:Thermodynamics
chemical_list: D037741:Fullerenes; D006046:Gold