Profile

Dr. Adam Sweetman is group leader of the high resolution scanning probe group at the University of Leeds. Adam completed his PhD at the University of Nottingham in 2010, where he subsequently took up a Postdoctoral position in the group of Prof. Philip Moriarty. While at Nottingham, he was the recipient of a JSPS Short term Fellowship and JSPS BRIDGE fellowship, which he held at NIMS in Tsukuba, Japan. From 2014 – 2017 he was awarded a Leverhulme Early career fellowship in the field of atomic scale manipulation, and in 2018 he moved to the School of Physics and Astronomy at the University of Leeds to take up a University Academic Fellowship. He currently holds a Royal Society University Research Fellowship and ERC Starting Grant, and his research interests are focused on understanding and quantifying the interactions that occur between single atoms and molecules via the use of low temperature scanning probe microscopes (in particular non-contact atomic force microscopy), and their simulation via ab-initio calculations.

Responsibilities

• MSc Physics Programme Manager

Research interests

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. Our 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 has focused 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 using the FHI-aims, SIESTA and CP2K packages 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.

Professional memberships

• Chair of IOP Nanoscale Physics and Technology Group

Projects

<li><a href="//phd.leeds.ac.uk/project/1120-novel-functional-nanomaterials-synthesised-via-self-assembly-of-molecular-arrays--">Novel functional nanomaterials synthesised via self-assembly of molecular arrays </a></li>