title: Single-Molecule Rotational Switch on a Dangling Bond Dimer Bearing.
abstract: One of the key challenges in the construction of atomic-scale circuits and molecular machines is to design molecular rotors and switches by controlling the linear or rotational movement of a molecule while preserving its intrinsic electronic properties. Here, we demonstrate both the continuous rotational switching and the controlled step-by-step single switching of a trinaphthylene molecule adsorbed on a dangling bond dimer created on a hydrogen-passivated Ge(001):H surface. The molecular switch is on-surface assembled when the covalent bonds between the molecule and the dangling bond dimer are controllably broken, and the molecule is attached to the dimer by long-range van der Waals interactions. In this configuration, the molecule retains its intrinsic electronic properties, as confirmed by combined scanning tunneling microscopy/spectroscopy (STM/STS) measurements, density functional theory calculations, and advanced STM image calculations. Continuous switching of the molecule is initiated by vibronic excitations when the electrons are tunneling through the lowest unoccupied molecular orbital state of the molecule. The switching path is a combination of a sliding and rotation motion over the dangling bond dimer pivot. By carefully selecting the STM conditions, control over discrete single switching events is also achieved. Combined with the ability to create dangling bond dimers with atomic precision, the controlled rotational molecular switch is expected to be a crucial building block for more complex surface atomic-scale devices.
authors: Centre for Nanometer-Scale Science and Advanced Materials, NANOSAM, Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University , Łojasiewicza 11, PL 30-348 Krakow, Poland.
authors: Szymon
authors: S
authors: Godlewski
authors: Institute of Materials Research and Engineering , 2 Fusionopolis Way, Innovis, #08-03, Singapore 138634.
authors: Hiroyo
authors: H
authors: Kawai
authors: Centre for Nanometer-Scale Science and Advanced Materials, NANOSAM, Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University , Łojasiewicza 11, PL 30-348 Krakow, Poland.
authors: Marek
authors: M
authors: Kolmer
authors: Centre for Nanometer-Scale Science and Advanced Materials, NANOSAM, Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University , Łojasiewicza 11, PL 30-348 Krakow, Poland.
authors: Rafał
authors: R
authors: Zuzak
authors: Institute of Chemical Research of Catalonia (ICIQ) , Av. Països Catalans 16, 43007 Tarragona, Spain.
authors: Antonio M
authors: AM
authors: Echavarren
authors: Nanosciences Group & MANA Satellite, CEMES-CNRS, 29 rue Jeanne Marvig, F-31055 Toulouse, France & International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS) , 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
authors: Christian
authors: C
authors: Joachim
authors: Centre for Nanometer-Scale Science and Advanced Materials, NANOSAM, Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University , Łojasiewicza 11, PL 30-348 Krakow, Poland.
authors: Marek
authors: M
authors: Szymonski
authors: Laboratory for Chemical Technology, Ghent University , Technologiepark 914, 9052 Ghent, Belgium.
authors: Mark
authors: M
authors: Saeys
keywords: hydrogenated semiconductor surface; molecular rotor; molecular switch; organic molecule; scanning tunneling microscope; single-molecule devices; single-molecule manipulation; surface dangling bonds