Polarons, Superconductivity and Molecular Electronics

An electron moving through a solid is impeded by its interaction with lattice vibrations. The resulting quasiparticle, the polaron, is of importance in many processes.

A novel continuous-time Monte-Carlo technique allowing for polaron and bipolaron simulations has led to the prediction of superlight lattice bipolarons (Alexandrov, Hague, Kornilovitch and Samson). Bose condensation of these bipolarons is a proposed mechanism for high-temperature superconductivity.

Flux cloning and vortex nucleation in small superconductors have been described by Gulevich, Kusmartsev and Sobnack. The results are in agreement with experiments by Geim and Grigorieva (Manchester). Kusmartsev has pioneered research in polaronic strings, stripes and electronic phase separation.

Another topic of research is the intrinsic molecular switching mechanism responsible for the bistable current state of some molecules (Alexandrov and Bratkovsky). This research (in collaboration with Hewlett-Packard) is potentially useful for new molecular technologies in the computing industries.