Solid-state branch
IR Spectroscopy at High-Pressures
We employ IR spectroscopy at High-Pressures for the study of strongly correlated electron systems, characterized by strong Coulomb repulsion U. By modifying inter-atomic positions, pressure changes the bandwidth (W) of materials. The tuning of the U/W parameter permits to explore the complex phase-diagram of these fascinating materials, thereby accessing novel electronic and magnetic phases. With the help of these techniques we have addressed the electrodynamics of Vanadium Oxide compounds (see here, for a review), Charge-Density-Wave materials, and Pnictide Superconductors. |
THz Coherent Synchrotron Radiation
The THz range is highly requested for spectroscopy and imaging, by several different communitites, from solid-state physics to biology, biomedecine, industrial and security. In collaboration with the Elettra machine physics group, we have demonstrated the possibility of producing high power Coherent THz radiation, up to the mW range. The radiation emitted in bursts shows a wavelength distribution shorter than the nominal electronic bunch length, thus suggesting that the microscopic emission mechanism is due to the beam instabilities. |
Multigap Superconductors
THz Spectroscopy is a unique tool for the characterization of the Superconducting gaps. This is because it is a non-contact, bulk sensitive probe, with an exceptionally fine energy resolution (∆E ~ 1 cm-1 ~ 10-4 eV ). We employ THz spectroscopy for the study of Superconducting Gaps, with a special emphasis on multigap superconductivity. This topic, while being discussed since the 50's, remained essentially speculative up to 2001, when for the first time multigap superconductivity has been demonstrated to take place in a real material, as MgB2. Today the topic is extremely lively, because of the large interest raised by Pnictide Superconductors, which are also known to display multiple gaps. |
High-Pressure BiophysicsWe address the effects of pressure application (1-20 kbar) to explore the conformational landscapes of proteins and amyloid aggregates. Pressure effects on proteins obey the principle of Le Chatelier, which states that after pressure application the system shifts towards a new equilibrium position charaterized by the occupation of a smaller volume. The pressure-induced changes are monitored in the mid-infrared through the study of the amide bands. Pressure can be used to drive proteins out of their native folding state. The application of pressure inhibits the formation of amyloid aggregates, and can be used to break amyloid fibrils and revert the protein to its monomeric form. These studies are relevant to the understanding of amyloid-related diseases as Alzheimer, Parkinson, type 2 diabetes, Huntington's, Creutzfeld-Jakob, etc. |
