HMC Physics Colloquium
Tuesdays at 16:30 in Shanahan Center for Teaching and Learning, Room B460
Sharon Gerbode
Harvard University
Jan. 18, 2011
In this talk, I will describe recent experiments on colloidal crystals composed of microscopic peanut-shaped dimer particles suspended in water. The Brownian particle motion introduces thermal fluctuations, driving crystallization into a periodic structure of densely packed particles. Unlike crystals of atoms, colloidal crystals can be directly visualized with an optical microscope, offering the unique opportunity to watch the time evolution of a thermodynamic system, particle by particle. In our studies of crystalline colloidal dimers, we "poke" the crystal by manipulating individual particles with optical tweezers. We find that the relaxation dynamics of the system back to its crystalline configuration is surprisingly slow and displays features that are typically associated with disordered glassy systems.