Expert in: Disordered solids
LEWIS, Laurent J.
- Numerical simulation
- Materials science
- Computational techniques, simulation
- Amorphous semiconductors, metals, and alloys
- Disordered solids
- Laser-beam impact phenomena
- Molecular dynamics and particle methods
- Nanoscale materials and structures: fabrication and characterization
- Thermal properties of small particles, nanocrystals, nanotubes and other related systems
My research program examines the general theme of computational physics of materials. We use powerful computers to probe the structural and other behaviour and properties of materials, and the "structure-function" relationship. Our preferred approach is molecular dynamics, which involves integrating the equations of motion of a system of atoms under the effect of forces from "potentials"; they may be generic (Lennard-Jones, for instance), empirical or semi-empirical, or even ab initio. The size of the systems depends on the potential used and varies from tens or hundreds of atoms to several million.
We study a vast range of problems, but we are particularly interested in the following ones, just as an example: (i) laser ablation and laser-material interactions; in this case we are trying to understand how matter reacts to powerful, short laser pulses - ejection mechanisms, structural modifications of the target, properties of the ablation plume, etc. (ii) disordered, amorphous or vitreous materials; in this field, we are trying to understand the short-, medium- and long-term structure of materials like amorphous silicon, metallic glass, etc. (iii) thermal properties of nanoscopic materials; we are trying to determine how heat dissipates near nanometric structures and how it moves in molecular junctions between nanoparticles, in particular.