Abstract

This talk will describe new routes to melting exemplified by so-called Wigner lattices.

Wigner lattices are nearly defect-free, and they are formed through repulsive interactions exclusively. The absence of defects inhibits melting, making the crystal much more stable, and it reduces the energy difference between crystal and liquid. Thus, the melting transition acquires a distinct second-order character, even though it is strictly a first-order transition.

This form of melting was first proposed by the German physicist Max Born nearly 80 years ago. It is only now that its study can be carried out.

About the Speaker

David Weitz  is the Mallinckrodt Professor of Physics and Applied Physics at Harvard University.

After receiving is Ph.D. in physics from Harvard University, he joined Exxon Research and Engineering Company, where he worked for nearly 18 years. He then transferred to academia, as a professor of physics at the University of Pennsylvania. In 1999, he moved to Harvard University.

Weitz leads a group studying soft matter science with a focus on materials science, biophysics, and microfluidics. He has co-founded several companies to commercialize some of the microfluidics work developed in his lab.

About the Soft Matter Incubator

The Soft Matter Incubator (SMI) is part of the Center for the Science and Technology of Applied Materials and Interfaces (STAMI), It addresses fundamental science questions about soft matter, which is characterized by large response functions governed by large entropic contributions to the free energy. 

SMI is interested in soft matter in equilibrium and out-of-equilibrium, as well as in active matter, where there is energy input at the single-particle level. Polymer solutions and gels, colloidal suspensions, liquid crystals, aerosols, granular matter, emulsions,  and foams are all examples of soft materials. Of particular interest are studies addressing the origin of collective, many-particle behavior.