Condensation, clustering and self-assembly of patchy colloids

Prof. Francesco Sciortino
Università di Roma "La Sapienza"

ABSTRACT:

Recent advances in the chemical synthesis and fabrication of nanometer-to-micrometer sized particles have produced a wide variety of new designs. These new particles are poised to become the 'atoms' and 'molecules' of tomorrow' s materials if they can be successfully assembled into useful structures. One challenge is to organize them into structures for functional materials and devices. A promising approach is self-assembly, which is the spontaneous organization of matter into ordered arrangements. To tailor the material behavior at the macroscopic level, through control of the interactions and of the self-assembly process requires a deep understanding of the modification to the phase diagram induced by the presence of patchy or specific interactions as well as effect induced by the anisotropy in shape and particle surface composition.

In this seminar I will illustrate some recent activities devoted to the investigation and control of quantum light. The experimental implementation of some of the most basic quantum operations, like single-photon creation [1,2] and annihilation [3], has allowed our group to generate and manipulate light at the most accurate levels. This, together with advanced techniques for the complete characterization of the generated light states, has led us to probe fundamental rules of quantum physics (like the commutation relations [4-6]), and develop new tools (like noiseless linear amplification [7]) for future quantum technologies.

In the lecture, I will discuss some of the most recent attempts to engineer non-isotropic colloidal particles, moving beyond the case of hard-sphere colloids, short-range attractive colloids and symmetrically charged colloids. I will then discuss the effect of the non-sphericity on the phase diagram of the system, showing how dynamical arrest can arise from bonding (differently from the case of glasses where packing plays a major role). Finally, I will show how unconventional phase diagrams can arise in extreme cases of colloids interacting with a significant non-isotropic potential (Janus particles) or dipolar-like interactions.