Dionys Baeriswyl

Dionys Baeriswyl was a Swiss theoretical physicist and Emeritus Full Professor at the University of Fribourg in Switzerland, who worked on Condensed matter physics. Baeriswyl was known primarily for his contributions to the theory of strongly correlated electron systems. In particular, he had conducted fundamental work on conjugated polymer and other quasi-one-dimensional electronic systems, emphasizing early on the importance of electronic correlations in these systems. In addition, Baeriswyl was known for his work on variational wave function approaches to one- and two-dimensional correlated electron systems, applying them to the Peierls transition and the Mott transitions as well as to superconductivity in high-Tc cuprate. In the course of this work, he introduced the variational wave function known as the Baeriswyl wave function, which can be viewed as the strong-coupling complement to the Gutzwiller wave function. While the Gutzwiller wave function incorporates correlation effects into the free electron state, the Baeriswyl wave function incorporates itinerant electron movement into a localized, strongly correlated insulating state.