# David J. Thouless

Wolf Prize Laureate in Physics 1990

The Physics Prize Committee has unanimously selected the following two candidates to equally share the Wolf Prize for 1990: David J. Thouless and Pierre-Gilles de Gennes.

**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.”

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.