Harry Thomas was born on 16.8.1927 in Rostock, Mecklenburg-Vorpommern, where he finished the ground and high school and started his study of physics. He received his PhD from the University of Clausthal, Lower Saxony, with a thesis on thin films and plasma excitations. Together with his good friends M. Methfessel and B. Lüthis he moved in 1956 to the IBM research laboratory in Switzerland, which had been founded in Adliswil in the same year.
Six years later the lab was relocated to Rüschlikon, where in 1957 Harry met K. Alex Müller for the first time. This meeting initiated a long friendship and an extraordinarily fruitful collaboration from which essential papers on structural phase transitions emerged. They collaborated especially in the field of perovskite oxides and were able to analyze the transitions and the related soft lattice modes. In 1957 Harry also became the head of the theory group which attracted many high ranking visiting scientists. When A. Speiser, the founder of the lab, changed to Brown Bovery in 1966, Harry was nominated as leader of the complete lab. In 1969 this position was given to the Swiss scientist H. Eichenberger, which motivated Harry to accept a full professorship at the University of Frankfurt. In the following years he continued his studies on structural phase transitions with emphasis on elastic deformations and coupling to strain fields. A close collaboration with J. C. Slonczewski produced many highly cited papers.
Since in Frankfurt the early 70ties were governed by heavy students' agitations he decided to follow a call to the University of Basel, Switzerland, in 1973. In just this year a complete reconstruction of the physics institute in Basel was under way, whereby the formerly independent institutes, physics institute, institute for applied physics and institute for theoretical physics, merged together to a single Physics Institute. Together with H. J. Güntherodt he served as founding professor of solid state physics which only in the late fifties became an acknowledged section of physics. In the following years until his retirement his probably most important work was established. The close collaboration with P. Hänggi et al. was based on their common interest in stochastic processes, their time evolution, the symmetry properties. With E. Magyari and coworkers he focused on solitary excitations in ferromagnets and nonlinear processes involved in domain formation; with H. Büttiker he investigated current instabilities; with T. Gyalog et al. he concentrated on atomic friction. During the same period and in collaboration with K. H. Höck and H. Nickisch the important work on Jahn-Teller polarons appeared which was the motivation to search for superconductivity in cuprates and initiated the field of high temperature superconductivity. After the Nobel prize was awarded to the Swiss scientists Georg Bednorz and K. Alex Müller, Harry worked on the manipulation of vortices in thin films of cuprates, the magnetic field and order parameter dependence. After his retirement in 1995 he remained open minded with respect to actual new problems in physics and started new working areas. His main fields of interest moved to quantum computing, resonance scattering of synchrotron radiation, the complexity of microscopic to macroscopic dimensions, the magnetic confinement of repelling Bloch waves. This list is, however, not complete.
His professional competence enabled him already in early years to be the editor of the IBM publications, which required that he read all of them. Together with G. Harbecke and K. A. Müller he became later on chief editor of Zeitschrift für Physik. He participated in numerous conferences, mostly as invited speaker. In particular, he enjoyed the workshops in Erice, Sicily, where his wife Waltraud accompanied him to undertake together long walks through the beautiful landscape of Sicily. During his time in Frankfurt and Basel he trained a large number of PhD students and encouraged their habilitation, including my own. Here he showed his human friendly mind which positively supported the students and enabled them to reach their goals.
Harry could intensively concentrate on special problems, thereby forgetting to sleep and coming up with solutions the next morning. Besides his deep interest and understanding of physics he was always open to humanistic problems, liberal, reliable, duteous. He was just a good and loyal friend. He was not only competent but also adorable and full of human warmth. The welfare of his family and friends was a central issue of his concerns.
Harry Thomas died on 18 July 2010 in consequence of a pneumonia. With his death we loose an excellent scientist, a wonderful teacher and a good friend.
