Molecular Nanoscience

The focus of the group is the investigation of various molecules (or nanostructures) on surfaces. Diverse mechanical, magnetic, and electronic properties are studied using surface sensitive techniques: X-ray Photoelectron Spectroscopy (XPS), Scanning Probe Microscopy (SPM), X-ray Magnetic Circular Dichroism (XMCD) spectroscopy, Low-Energy Electron Diffraction (LEED) and others. Currently our main interest is concentrated at controlling spins in adsorbed molecules by chemical and/or physical switches. We perform in-depth studies of various molecule-switch combinations in order to understand the mechanisms ruling the magnetic response. Density Functional Theory (DFT)+U calculations performed by our collaborators (see below) give a very important input to achieve this goal.

2D Checkerboard lattice of Fe and Mn bearing molecules providing a 2D spin array which is switchable by chemical ligation.

The group is developing and investigating functional on-surface supramolecular architectures. Self assembly and supramolecular chemistry - in analogy to life's biochemistry - allow for the fabrication of complex functional architectures from specific atomic and molecular building blocks. Surprisingly supramolecular chemistry also works at surfaces and in complete absence of solvents i.e. in the hands of surface scientists. Stability up to temperatures of a few hundred C, the addressability of individual functional units and the ability to control the dose of the different components in precise sub-monolayer fractions provide advantages of the such produced supramolecular architectures. The physics and chemistry of these unprecedented systems, which are addressable by scanning probes, and in parallel by photon probes using synchrotron light provide insight into novel materials in their assembly, their electronic and spintronic properties which emerge from the interaction of their components down to the scale of single atoms, molecules and bonds.