Channeling in Solids.
Planar, axial, transfer matrix technique, inter-atomic potentials, stability

Plasmons in layered structures
Quantum theory

Fermion bosonisation in one dimension
Jordan's theory, extended to the Luttinger liquid

Charge-density waves
Theory, new pinning mechanism in KCP, due to modulated distribution of impurities

Many-Body
Studies on fermion interaction effects

Four-fermion condensate
Two-pairs supefluid correlations, effective four-body interaction, alpha-particle structures in atomic nuclei, bi-excitons

Configurational transitions in bio-molecules
Enhancing reaction rate

High-T_c superconductivity
Effective hole interaction through localized modes of lattice distortion and vibration