The Physics Prize Committee has unanimously selected the following two candidates to equally share the Wolf Prize for 1990:
Pierre-Gilles de Gennes
College de France
Paris, France
David J. Thouless
University of Washington
Seattle, Washington, USA
for a wide variety of pioneering contributions to our understanding of the organization of complex condensed matter systems, de Gennes especially for his work on macromolecular matter and liquid crystals and Thouless for his on disordered and low-dimensional systems.
Among his important contributions to many different parts of condensed matter physics, including magnetism, superconductivity and scattering studies, Professor Pierre-Gilles de Gennes has provided fundamental concepts for the development of macromolecular science. These have provided a firm foundation for analyzing complicated but important processes. He analyzed the dynamics of correlated motions of polymers in their complex environment and predicted their critical phenomena by extending the use of path-integral methods, developing applications of scaling ideas and introducing the concept of reptation. This work has stimulated many experiments which have confirmed his concepts and their relevance. It has energized the whole field of the physics of long chained macromolecules, much of the new work being done by former students and young colleagues. These achievements also hold promise for future applications to biological systems.
Professor David J. Thouless has provided major theoretical contributions to our understanding of extended systems of atoms and electrons, and of nucleons. These have involved especially superconductivity phenomena, properties of nuclear matter, and excited collective motions within nuclei. His work on disordered systems provided key ideas for understanding electronic transport processes in systems where Anderson localization plays an important role, and indicated measurable consequences of this localization in thin wires. His contributions to spin glass theory have been substantial and· important. With J. M. Kosterlitz, he developed a theory of vortex-unbinding transitions in two-dimensional systems with continuous symmetry. This has had remarkable consequences and many applications in other areas of physics. He has made clearly apparent the significance of topological concepts (and their related variables) in condensed matter physics and demonstrated their importance for the Quantum Hall effect.