University of Tartu ranks among the world’s top institutions in physics

Toomas Plank, Director of the Institute of Physics at the University of Tartu, said that the university’s success in physics is not the result of the work of individual researchers or a few laboratories, but reflects the collective efforts of the entire institute. “Over the last decade, the numerous high-level achievements of the Laboratory of Theoretical Physics and the Laboratory of Plasma Physics have attracted lively response from the scientific community and risen to the top worldwide in terms of citations in physics. Also, the Laboratory of Physics of Ionic Crystals, with research topics spanning materials science and physics, have strongly influenced the field. Visiting Professor Tomi Sebastian Koivisto, Associate Professor emeritus Matti Laan, Associate Professors Peeter Paris, Manuel Hohmann and Laur Järv, as well as Professors Aleksandr Luštšik, Marco Kirm and Associate Professor Vitali Nagirnõi, whose work focuses on both materials science and physics, are just a few examples of scientists whose work has gained substantial international recognition,” said Plank.

Nationally recognised cutting-edge research

Active international research collaboration has also significantly supported the rise to the global top in research impact. According to Plank, the above-mentioned researchers have been consistently involved in the activities of several Estonian centres of excellence in research. Notably, both fundamental research and experimental and applied research have been influential.

For example, researchers from the Laboratory of Theoretical Physics participating in the centre of excellence Foundations of the Universe (CoE 202) study whether some of the greatest mysteries of modern science – such as dark energy driving the expansion of the Universe or inflation in the early Universe – may point to limitations in Einstein’s theory of general relativity. Just as Einstein once extended Newton’s ideas, there is now reason to think beyond Einstein. In 2020, Laur Järv, Manuel Hohmann and Margus Saal received the Estonian national research award in exact sciences for their research cycle “Extended geometrical theories of gravity”. In 2023, the same award was granted to Tomi Koivisto and Luca Marzola from the National Institute of Chemical Physics and Biophysics for their research cycle “The metageometrical basis of physics”.

In the centre of excellence in Sustainable Green Hydrogen and Energy Technologies (CoE 210), researchers from the Laboratories of X-Ray Spectroscopy and Physics of Ionic Crystals, led by Academician Enn Lust, analyse the physical processes occurring in ultrafast scintillators and other highly efficient light-emitting materials. In addition to energy production, the development of this technology should focus on applications in lighting and other fields. For instance, UV-C radiation is used to reduce harmful bacteria on surfaces where they may pose a risk to human health.

International collaboration

“References to our scientific articles show that our ideas have proven fertile and, somewhat unexpectedly, brought us to the centre of international scientific debate. Another sign of impact comparable to citation numbers is that in recent years, several postdoctoral researchers and visiting students from major European countries have come to Tartu to continue their research using their own funding,” said Laur Järv, Head of the Laboratory of Theoretical Physics. The laboratory organises the international conference Geometric Foundations of Gravity and eXtensions, which will be held for the tenth consecutive year this summer.

Physicists and materials scientists from the Institute of Physics are also contributing to the EUROfusion programme, which coordinates the development of fusion-based energy sources in the European Union. The programme aims to prepare the scientific groundwork for next-generation fusion reactors such as ITER and DEMO. This involves extensive use of existing reactors in Europe and at partners’ sites elsewhere, and the development of new materials and analytical methods. Within this programme, researchers from the Laboratory of Plasma Physics are developing a laser-based diagnostics method to determine the condition of reactor walls.

An important foundation for the achievements of physicists and materials scientists is the world-class research infrastructure included in the Estonian Research Infrastructure Roadmap. Infrastructure objects such as the Center of nanomaterials technologies and research (NAMUR+), the Estonian beamline at the MAX IV synchrotron radiation source (FinEstBeAMS), the European Spallation Source (ESS), and the European Organization for Nuclear Research (CERN) provide outstanding experimental and theoretical opportunities for conducting state-of-the-art research. They are also a good springboard for the University of Tartu to join the top 1% of the world’s most highly cited research institutions in physics.

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The FinEstBeAMS beamline mentioned above was established by University of Tartu physicists in international collaboration with Finnish universities at the laboratory in Lund. It is used to investigate the electronic structure of solids, liquids, and gaseous substances, including clusters, and for energy dissipation studies. Since 2017, the international user community has published 109 scientific papers on the FinEstBeAMS beamline; this result ranks second among the 16 beamlines at MAX IV.

International collaboration with CERN includes aerosol formation studies in the CLOUD experiment with muons to understand atmospheric processes; particle physics research; development of new detector materials for calorimeters; development of new materials for accelerator technologies; and the physics of the underlying processes. Research groups from the Institute of Physics and the Institute of Technology are involved in the research. The new materials find applications beyond fundamental physics, for example, in space technology and medical imaging, where images of the interior of the human body are needed (such as X-ray and ultrasound imaging, endoscopy, etc.).

Although the ESS has not yet been completed, the University of Tartu neutron research groups at the Institutes of Physics and Chemistry use other neutron sources worldwide to study the specific features of photosynthesis and to develop new functional materials for energy technologies and other applications.