Freek Massee
     Laboratoire de Physique des Solides, CNRS


Home-built STM headHome-built STM head.

As a experimental condensed matter physicist, my research interests are primarily focussed on emergent quantum materials such as high-Tc superconductors, heavy fermion systems and colossal magnetoresistant manganites. Using scanning tunnelling microscopy and spectroscopy, I try to unveil the atomic scale properties of these materials and to determine the interactions that are responsible for their unexpected macroscopic behaviour - in particular the interactions between electrons, their spins and the lattice they inhabit. To learn as much as possible about these systems I further continuously strive to improve existing, and design new instrumental tools. One example of this is the development at the Laboratoire de Physique des Solides in Orsay, together with experts in cryogenic, high frequency, low noise amplification at C2N, of cryogenic circuitry operating in the MHz regime. Using this circuitry, the home-built microscope I have set up in France (or any other scanning tunnelling microscope for that matter) can perform shot-noise measurements at the atomic scale, while it still also operates as a normal scanning tunnelling microscope. Since the shot-noise of a tunnelling current depends directly on the interactions between tunnelling electrons, as well as their charge, a wealth of information that was previously difficult to determine can be directly accessed. Furter details and examples can be found in the highlights and publications sections. For more details on 'traditional' scanning tunnelling microscopy click here.