Substrate-supported atomic-scale In nanowires:Structure, phase transition and spectroscopic properties

• Applicant: Professor Dr. Wolf Gero Schmidt
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2007 to 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 46772759

The proposed joint theoretical-experimental project aims to extract a deeper understanding of the prototypical In nanowires on Si(111) from spectroscopic signatures. In addition to the ground-state structure, the impact of adatoms and defects on the metal-insulator phase transition will be explored by combining non-contact surface optical spectroscopy with first-principles calculations based on density-functional theory (DFT). With optical spectroscopy into the far infrared (FIR) as well as Raman spectropscopy we measure electronic excitations due to inter- and intraband transitions as well as surface vibrations. The comparison of the measured spectroscopic fingerprints with calculated signatures allows for probing structural candidates and is expected to lead to a thorough understanding of the relation between the nanowire geometry and electronic properties. Furthermore, the calculations will help to rationalise the energetics and driving forces of the temperatureinduced phase transition and will be used to relate the Landauer conductance of the nanowires to their structural properties and external modifications.

• DFG Programme: Research Grants