Atomic resolution imaging

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Molecular imaging and modelling

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Atomic manipulation

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Imaging and manipulation of single atoms and molecules

Atomic scale manipulation via chemical interactions
The development of scanning probe microscopes such as the scanning tunnelling microscope (STM) and non-contact atomic force microscope (NC-AFM) has permitted the investigation of crystal surfaces and adsorbed molecules with atomic resolution. These same techniques even permit the controlled manipulation of single atoms via physical and electronic means. My research focuses on the measurement of inter-atomic interactions, and the manipulation of single atoms and molecules via the physical forces between the tip and sample.

Mapping intermolecular interactions and sub-molecular imaging
Recent developments in NC-AFM techniques now mean it is possible to image the intramolecular geometric structure of planar organic molecules, leading to an extremely active research field. Our research focuses on the potential for these techniques to provide information about the intermolecular interactions present between closely spaced molecules. This requires the development of a judicious understanding of the behaviour of the atoms trapped in the tip-sample junction, and the response of the physical and electronic structure of the sample to the applied forces.

Ab-initio Simulation methods
An important aspect of scanning probe experimental research is close collaboration with theoretical groups in order to interpret certain aspects of the experimental data. We use a number of simulation approaches, including density functional theory (DFT) simulations to elucidate the origin of the image contrast in both STM and NC-AFM images.

Scanning probe and UHV instrumentation
The ability to perform atomic scale investigation is only possible due to the development of extremely sophisticated and robust instrumentation. Our work combined necessitates the generation of ultra high vacuum (UHV), extreme vibration isolation, cryogenic cooling to liquid helium temperatures and high sensitivity electronic detection. Improvements in SPM instrumentation therefore form a key aspect of the work performed in our laboratory

See my website for further details of my research

 

Persons involved

Dr Adam Sweetman