Navigation auf




Preface - Thomas Gehrmann, Department Head

Exhibition in the Lichthof at Irchel campus to honour Nobel Laureate K. Alex Müller.

With a total of 24 research groups, the Department of Physics of the University of Zurich covers a variety of subfields of physics. Experimental activities include particle and astroparticle physics, hard and soft condensed matter physics, surface physics and nanoscience, as well as the physics of biological systems. Theoretical groups work on precision calculations of processes in quantum chromodynamics and new theories beyond the standard model of particle physics, astrophysics and general relativity, as well as topological concepts in condensed matter physics. Other physics-related groups from within the Faculty of Science and beyond are affiliated to our department, and our home page gives links to their research. Together, we can offer a broad and high quality spectrum of lecture courses as well as Bachelor, Master and semester projects to our students. The infrastructure department consisting of excellent mechanical and electronics workshops. Efficient IT and administrative support teams complete our attractive research environment.

During the year 2023, the refurbishment of the laboratory building 56 of the Physik-Institut was completed. The new building offers state-of-the-art clean-room facilities and extra laboratory space for various groups. A major initial usage of the clean-room will be the assembly of the central silicon detectors for the high-luminosity phase of the CMS experiment at CERN. In the medium term, building 56 could become home to the planned DEMETER center, which is a joint initiative with colleagues at PSI to foster detector development for applications in various subfields of physics.
The start of the year was marked by the passing of our former colleague K. Alex Müller, who died on January 9, 2023 at age 95. The eminent physicist was awarded the 1987 Nobel Prize in Physics with J. Georg Bednorz for the discovery of high-temperature superconductivity. K. Alex Müller was both a professor at the University of Zurich and a fellow at the IBM Research Laboratory in Rüschlikon. In his honour, our department set up an exhibition on high-temperature superconductivity and its applications in Irchel Lichthof during the fall semester. The display was very well-received by students and academics from all faculties. We also co-organized a festive symposium that brought together friends and colleagues of K. Alex Müller, sharing recollections of their joint work and highlighting its lasting impact and present-day relevance.
In 2023, our department was very happy to welcome two new research groups in theoretical physics: Max Zoller and Tomáš Bzdušek both obtained SNSF Starting Grants and joined our institute as assistant professors. Max Zoller and his group perform precision calculations in particle theory, while Tomáš Bzdušek and his group investigate topological phases and related phenomena.
Our department made substantial contributions to community-building and outreach events such as our traditional hiking day or the christmas dinner for the members of our institute and various events for high-school students including specific workshops and the participation in the international masterclasses in particle physics. Finally, our institute organised an open day and contributed to the Scientifica 2023 with an exhibit on the basic building blocks of matter, with guided visits to the XENOSCOPE facility, a fun show on physical effects and with an astronomy theatre performance.
This booklet aims give a broad idea of the wide range of research pursued in our department and refers the more interested reader to the research websites. Presenting individual highlights with pride, we thankfully acknowledge the continued support from the Kanton Zürich, the Swiss National Science Foundation, the European Commission, and others who have made this fundamental research possible.


In Memoriam Prof. em. Dr. Franz Waldner, 1928 –2023

Prof. em. Dr. Franz Waldner was Professor for Experimental Physics at our institute from 1964 until his retirement in 1995.

After completing his training as a primary school teacher, Franz Waldner worked for three years before continuing his training as a secondary school teacher and teaching at this level for a short time. From 1955 he studied physics at the University of Zurich and obtained his doctorate in 1963 under Professor Ernst Brun with a thesis on "Paramagnetic electron resonance of Fe3+ in MgAl2O4". In 1964 Franz Waldner was appointed assistant professor and in 1979 full professor in experimental physics at the University of Zurich. In 1969 he spent a year at the Argonne National Laboratory (USA), where he was not only very curious to learn about new research approaches and a different institute culture, but also intensively engaged with American society.

Franz Waldner’s research interests were very broad, ranging from electron spin resonance, crystallography, magnetism and superconductivity to complex non-linear systems and the movement of desert ants.

While still a student, he worked as an assistant in Hermann Wäffler’s group and, among other things, carried out measurements of cosmic radiation on the Jungfraujoch. As an assistant professor, Franz Waldner set up the electron spin resonance (ESR) laboratory at the former Physics Institute, where the measurement of paramagnetic ions as probes in single crystals was started. In collaboration with the future Nobel laureate Professor K. Alex Müller and the crystallographer Professor Fritz Laves, ESR was used for the first time to determine the structure of solids, an essential basis for later studies of high-temperature superconductivity. Later, the ESR research group studied quasi-two-dimensional magnets in the form of layered structures. It was shown experimentally that the dimensionality essentially determines the critical dynamics. Very weakly damped spin waves could be excited at low dimensionality and used to study non-linear phenomena. This laid the foundation for his later research on superconductors, quantised lattice vibrations, spinors, skyrminons and solitons.

After his retirement, Franz Waldner continued to work intensively on scientific topics, mainly from a theoretical point of view and with the help of simulations. He regularly published the results. One of his latest publications, which appeared in 2018, describes a model with random perturbations that describes the search pattern of desert ants.

Franz Waldner’s research was characterised by an incredible curiosity and interest. He successfully transferred this to his employees time and time again. He was open to many new ideas and willing to break new grounds. He is described as an internationally recognised and well-connected, modest scientist with a generous personality, to whom research and findings were more important than his own person.

In addition to his in-depth specialist lectures, Franz Waldner also taught first-year medical and physics students for many years. He understood how to present complex topics in a clear, didactically sophisticated and humorous way, and was not shy about going to a conference to demonstrate a soliton with a vector arrow.

Franz Waldner took great care of his doctoral and diploma  students. He was always available to answer questions and for discussions and looked after the staff in his group with great commitment.
Even after his retirement, Franz Waldner remained very close to the Institute, taking an interest in current research topics and innovations in the workshop. He visited the institute on Open Days and joined the Christmas dinner, and even in his old age took part in the traditional Institute walk.

In Memoriam Prof. em. K. Alex Müller, 1927 - 2023

Prof. Dr. Dr. h.c. mult. K. Alex Müller, IBM Fellow, Nobel Prize Winner in Physics 1987,  was Professor for Experimental Physics at our institute from 1970 until his retirement in 1994.
K. Alex Müller's scientific career path started with the studies of physics at ETH Zurich where he was intensely influenced by Prof. Wolfgang Pauli. His diploma work was supervised by Prof. G. Busch, who was also the supervisor of his PhD thesis which dealt with the paramagnetic resonance in the newly synthesized double perovskite SrTiO3.
 K. Alex Müller started his professional life as head of the magnetic resonance group at the Battelle Memorial Institute in Geneva. Upon the recommendation of Prof. E. Brun he did his habilitation at the University of Zurich in 1962. In view of his high scientific impact, the IBM Zurich Research Laboratory offered him in 1963 the position of a researcher where he was promoted to a group leader of the physics department in 1971, a position that he held until 1985. During this time his research focused on SrTiO3 and related perovskites with emphasis on their chemical binding, their ferroelectric and soft-mode properties, and later on their critical and multicritical phenomena at their phase transitions. His enormous successes in this field made him to one of the world leading experts in the research on ferroelectricity and structural phase transitions. In addition, his intimate knowledge of perovskites paved his way to superconductivity in this material class. In 1970 he was appointed as titular professor of the University of Zurich. A decisive moment in his career occurred in 1982 when he was nominated as IBM fellow.  This enabled him to decide freely and independently about his further research areas - a milestone on his way to the Nobel prize.
During a sabbatical leave starting in 1979 at IBM Yorktown Height (USA) K. Alex Müller paid for the first time attention to superconductivity and gained profound knowledge in this field. He was especially interested in oxide superconductors which were rare at that time. Theoretical ideas as developed by Prof. Harry Thomas and his group at the University of Basel gave him the impulse to concentrate on complex oxides with Jahn-Teller centers. Such ions provide a source of strong and unconventional electron-phonon interactions including polaron and bipolaron formation. Together with J. Georg Bednorz he started in 1983 a new research project concentrating on superconductivity in oxide Jahn-Teller systems. In 1986 they achieved the breakthrough with the discovery of cuprate high-temperature superconductors (HTSs), which only a year later in 1987 was honored with the Nobel prize in physics for both. In the same year, but before their nomination, K. Alex Müller was promoted to a full professor at the University of Zurich.
After the Nobel prize K. Alex Müller continued his work on cuprate HTSs by focusing on their pairing mechanism. Since his original concept for the discovery was based on a polaronic or bipolaronic mechanism, he initiated a project on isotope effects in cuprate HTSs where novel and unexpected isotope effects were discovered which confirmed his starting concept that the charge carriers in these superconductors are strongly coupled to the lattice,  i.e. that local lattice effects and inhomogeneity are relevant for superconductivity in cuprates. This notion is and was in strong contrast to the widely accepted conviction that the paring mechanism in the cuprates is of purely electronic origin.
Besides of his ingenious scientific achievements and engagements he was also a dedicated and inspiring teacher with profound interest in the students and their life. He attended the seminars at the Physik-Institut with deep scientific interest and was known for his perceptive and subtle questions and contributions. Up to an old age he stayed in close contact with the Physik-Institut and vividly took part in the social life.

Demonstration Experiments