Colloïdal systems

On one hand modern experimental techniques allow for the detection of individual positions of the colloids, using for instance confocal microscopy. On the other hand they allow one to design artificial colloids, with very specific properties such as self assembling or self propelling. These experimental achievements open a complete new field to theoretical statistical physics.

For instance modern measurements of colloidal crystals and disordered solids often use confocal microscopy where position fluctuations are observed in only a part of the system. We used analytical arguments, corroborated by extensive numerical simulation of hard-sphere crystals to develop the expected outcome of such measurements. Despite the apparently simple nature of the experimental technique the theoretical interpretation of data has turned out to be remarkably contaminated by artifact and has required a detailed theory of the full chain of data analysis.

The arrival of the experimental group EC2M around Olivier Dauchot who proposes studying the properties of active colloidal materials will lead to a true synergy between the theoretical and experimental work within the Gulliver laboratory. The experimental group is asking about building theoretical models to better understand the statistical mechanics of non-equilibrium materials, but also will require substantial numerical backup for the analysis of high volume video data. A major project in the group PCT will thus be associated with this new experimental project.