Manini's research on fullerene home | INFM | section G

Fullerene C₆₀ is sometimes seen as a big molecule, sometimes as a small hollow cluster, sometimes as a graphine sheet wrapped up to a spherical shape. Strong C-C σ-bonding stabilize a rigid backbone structure. Substantially delocalized π electrons account for the chemical and optical properties of C₆₀. Below 800 K, C₆₀ forms a Van der Vaals insulating solid of loosely bound individual molecules. Doping C₆₀ can form ionic materials (fullerides), showing novel and exciting properties such as superconductivity, organic magnetism, correlated Mott-insulating states.

The hole wave function in one of the 5 degenerate HOMO orbitals.

In collaboration with the SISSA condensed matter group, Manini has contributed some theoretical and computational research on C₆₀ ions and the fullerides, including:

• Coulomb repulsion among holes in C₆₀ fivefold degenerate last filled level (HOMO).
• Electron-phonon coupling in the positive and negative ions.
• The fullerene ions are exciting systems where several vibrational modes all coupled à la Jahn-Teller to a degenerate electronic state.
• In this electron-vibration coupling a Berry phase is often relevant.
• A successful calculation of the photoemission spectrum of the isolated molecule was carried out.

The distortion of the cation C60+ (coloured) with respect to the uncharged ideal icosahedral configuration. The distortion is amplified by a factor 10 to make it visible.	A colorful picture of C60. Distance modulates the color.