Karl-Heinz Rieder

Physicist and Surface Scientist Karl-Heinz Rieder died at Zurich, Switzerland, on March 7th, 2017 following prolonged struggle with illness.

Born on September 1st, 1942 in Eisenstadt in Österreich, he studied physics and mathematics at the University of Vienna. During this time he had the opportunity to attend the 1965 Lindau Nobel Laureate Symposium; direct contact with luminaries such as Hahn, Dirac und Heisenberg has greatly influenced Karl-Heinz‘ future career. In 1968, he obtained his doctorate at the Seibersdorf Labs (Austria) on inelastic neutron scattering of microscopic crystallites, a subject he continued working on subsequently at the Max-Planck-Institute for Solid State Physics in Stuttgart (Germany). In 1975 he moved to the IBM Research Center in Rüschlikon (Switzerland), where he and Thomas Engel developed helium scattering as a method to study surfaces. Ten years later, he was appointed at Freie Universität Berlin where he initially continued to work on elastic and inelastic helium scattering as well as high-resolution electron energy loss spectroscopy. Subsequently, he became active in low-temperature scanning tunneling microscopy and his setup was the second, after the IBM Almaden group, to manipulate individual atoms, molecules and surfaces. He became emeritus in 2005 yet continued to work as “Post-Professor” at the Swiss Federal Laboratories for Materials Science and Technology in Dübendorf (Switzerland) as well as at the Fritz-Haber-Institute in Berlin.

The accomplishments of Karl-Heinz Rieder cover a broad area of surface science. Based on his work, helium scattering – and most recently helium ion microscopy – have become established methods in the study of surfaces down to atomic resolution. During his tenure at the IBM Rüschlikon Research Center, he realized early-on the seminal impact of the new technique of scanning tunneling microscopy, that his colleagues Binnig and Rohrer were developing; he supported them by his knowledge about surface science as well as by loaning them his single-crystal samples for the initial measurements (which frequently he received back as molten lump of metal only) [1 ]. He might be most renowned for his later work at the Freie Universität Berlin developing methods for targeted manipulation of individual atoms and molecules at surfaces. His measurements offered insight into the fundamental physics of their place exchange processes as well as the associated forces and their excitation by transient attachment of electrons. A particular noteworthy accomplishment was the first chemical synthesis of an organic molecular species controlled and conducted using the scanning tunneling microscope as a nanoscale manipulator: in 2000 his group published the formation of a covalent bond between two surface-attached phenyl radicals induced by nudging the reactants in a controlled manner using the tip of a scanning tunneling microscope. Even graphene nanoribbons were studied in his group already in the 1990s.

Besides these contributions to science, he also remains remembered for his appreciation of the arts as reflected, for instance, in his humorous poem on the surface science community, that was included in the special is sue of the Journal of Physics published in his honor on the occasion of his 70th birthday [2 ]. As a clarinet and saxophone player he was part of a number of ensembles both during his time at IBM and earlier. For a while, he also devoted himself to painting.

His friends and colleagues miss Karl-Heinz Rieder foremost for his unique combination of scientific curiosity, brilliance in predicting experimental results, openheartedness, and supportiveness – always seasoned with kind humor. These attributes enabled his research group to prosper, its members to always feel appreciated and ready to tackle grand challenges. Despite the resulting success, Karl Heinz always remained humble; colleagues referred to him as the „quiet pioneer” [3 ]. His coworkers treasure the time they spent in his research group; some twenty of them are now faculty at various research universities in Germany, the United States, Austria, Switzerland and elsewhere. The guidance and the example they received from Karl-Heinz makes them better group leaders. He had a remaining impact on the sciences and the surface science community in particular, yet he is missed dearly for his kindness and generosity.

References

1. K.-H. Rieder, Chimia 66, 8 (2012).
2. L. Bartels and K.-H. Ernst, J. Phys. Condens. Matter 24, 350201 (2012).
3. G. Benedek, J. Phys. Condens. Matter 24, 350401 (2012).