The field of “ab-initio calculations of magnetic interactions” has developed intensively during the last decades and numerous applications have been able to provide theoretical understanding and prediction of a broad class of magnetic materials.

This involves traditional hard and soft magnetic materials to novel two-dimensional magnets, and from elemental solids such as Fe, Co, Ni, Gd to magnetic molecules containing hundreds of atoms.

I will review this research field which is not only important for novel technological development but also has a fundamental theoretical interest as a very nontrivial example of applications of basic quantum many-body theory to properties of real materials.

Every year the Young Speakers Contest is one of the highlights of the FYSICA meeting. It is a contest for the best oral presentation by an early career physicist (PhD candidate or post-doc) working at a university or research institute in The Netherlands. All participants of FYSICA 2026 can cast a vote to select a winner.

You want to participate? Please check this information.

President Kareljan Schoutens of the Physica Foundation will hold a laudatio and honour Bas van de Meerakker, winner of this year's Physica Prize.

An experiment in which two molecules collide with each other under well-defined conditions is one of the most fundamental ways to probe the interactions between individual molecules.

At temperatures approaching zero Kelvin, quantum mechanics starts dominating the collisions, leading to exotic collision mechanisms that have often been predicted theoretically decades ago, but have remained elusive experimentally.

We have developed a unique molecular collision experiment in which perfect control is obtained over the molecules before the collision using decelerators, and velocity map imaging is used to probe the molecules afterwards. This combination of techniques allows us to study collisions as a function of energy, and to visualize how molecular scattering processes evolve from classical mechanics at high energies to the pure quantum regime at temperatures down to 0.1 Kelvin.

This reveals the fundamental physics underlying the scattering process that originates from the wave-character of the molecules, such as diffraction of matter waves, quantum tunneling, and even the quantization of the relative motion between the colliding molecules.

(Photo: The Nijmegen Stark decelerator: the 2.6-meter-long structure consists of 316 pairs of polished stainless steel electrodes, and is used to prepare a packet of molecules prior to the collision. Credit: Ludwig Scharfenberg)

Are you one of the maximum of 25 challengers of Jan Groenendijk? Register quickly! Of course there will be lunch as well, it is available in the central hall, close to the checkers contest.

During the ALV we will discuss developments at our society, present the financial and board reports of 2025. A highlight will be the announcement of the future president of the NNV, who is chosen in a members' election in March. 

Documents for this meeting will be published on the NNV website at a later moment. 

Lunch will be available.

Lunch is provided for all participants, supporters and other attendants of this contest organized by SPIN, in which three students present their bachelor research. The winner will be announced later in the day.

Information to follow.

In this interactive session, Jean-Paul Keulen, editor in chief of the Nederlands Tijdschrift voor Natuurkunde and science journalist of NRC and the New Scientist, among others, will discuss how to keep the attention of readers when writing an article about sometimes very complicated research. The attendees can bring forward problems they face. 

Why are sexism, homophobia and racism still so prevalent in physics?

CERN, the largest physics laboratory in the world, welcomes scientists from 112 nationalities but still about 80% of them are white and 80% are male. Starting from her personal experience and aiming to demonstrate that in fact the personal is political, Dr. Pauline Gagnon examines why people from so many various groups have been historically excluded from physics and suggests a series of measures that could greatly improve diversity in physics.

Pauline Gagnon, retired Senior Research Scientist, completed her PhD in particle physics at University of California in Santa Cruz. Her research activities were mostly based at CERN, the European Laboratory for Particle Physics located near Geneva, where she worked as a Senior Research Scientist with Indiana University. She participated in the discovery of the Higgs boson in 2012 and looked for dark matter within the ATLAS experiment. After 2011 she joined the CERN Communication group, writing blogs and answering questions from numerous media worldwide. Explaining particle physics in simple and accessible terms became her trademark and in 2014 she wrote a popular science book called "Who cares about particle physics: Making sense of the Higgs boson, the Large Hadron Collider and CERN", which is also available in seven other languages. Since retiring she has given more than two hundred presentations to various audiences in fourteen countries, talking about physics and diversity issues.

This session of the NNV section history and foundations consists of lectures of Silvester Borsboom and Fred Muller.  

All Surface, No Substance? The Holographic Thermodynamics of Black Holes

Silvester Borsboom, Radboud Center for Natural Philosophy and Institute for Mathematics, Astrophysics and Particle Physics, Radboud University Nijmegen.

Black hole thermodynamics is one of the deepest but also one of the most puzzling areas of modern theoretical physics. Ever since Bekenstein and Hawking, it has been understood that black holes are not merely analogous to heat engines, but possess a physical temperature and an entropy that can, in specific string-theoretic models, be derived from microscopic constituents. These results indicate that black holes are truly thermodynamic.
However, black hole thermodynamics is uniquely superficial: its entropy scales with the horizon area rather than the volume. This strangeness relates to the holographic principle, originally proposed by Gerard ’t Hooft and Susskind, which posits that a region’s gravitational
degrees of freedom are encoded on its lower-dimensional boundary. Thus, the holographic principle dictates that the quantities appearing in black hole thermodynamics should be defined on surfaces rather than volumes.
As indicated, we know this to be the case for the entropy of a black hole. But thermodynamic systems normally come with a pressure and volume too. Since, holographically speaking, a volume is a surface, we should expect the pressure and volume of black holes to be area quantities, akin to the entropy. In this talk I present a recent proposal for holographic pressure and volume, demonstrating how these definitions resolve the area-volume paradox and reinforce the status of black holes as genuine thermodynamic systems.

In the Maelwael Van Lymborch House you will go on a journey through the exciting story of Herman, Paul and Johan van Lymborch, whose paintings garnered worldwide fame. Enjoy the brilliant art of the 'Rembrandts of the Middle Ages'and experience history in the authentic cellar of their 14th century workshop.

At De Vasim a bus is available to transport you to the museum and back.

Right next to De Vasim is the Waal Energy Industrial Park, formerly the site of the Gelderland Power Plant. Today, it is a place for activities related to sustainable (wind, sun and hydrogen) energy and logistics and water-related industries. Join this excursion for a tour of the park with its developers.

HFML-FELIX is a renowned national research institute, located in Nijmegen. Harbouring labs with high-field magnets and free-electron lasers, this facility enables scientists from all over the world to expose matter to extreme conditions and drive it into previously inaccessible states and phases.

At De Vasim a bus is available to transport you to HFML - FELIX and back.

In this session about two huge physics projects in Europa, we have two speakers:

The first is Pamela Ferrari, experimental physicist and professor of High Energy Physics at Radboud University in Nijmegen. She holds a leading position at the ATLAS experiment at CERN in Geneva, an international collaboration of more than 5,000 researchers that discovered the Higgs particle in 2012.

The second speaker is Stan Bentvelsen, Chief Science Officer of the organization Einstein Telescope Nederland (ET-NL), which plays a co-ordinating and pioneering role between all parties in the Netherlands working towards the telescope's arrival in the Euregio Maas-Rijn region. 

In this focus session the exciting research of the RU's Institute of Molecules and Materials, the High Field Magnet Laboratory and the Donders Centre for Neuroscience will be discussed.

Exam writers are regularly inspired by current scientific research. It is a challenge to translate and simplify this research into a problem that students can solve. During this educational session, exam writers are happy to take you along on the long journey of discovery from a scientific publication to a problem for a physics final exam.

More information to follow.

What career lies ahead for you as a physics student? In this interactive session phycisists from several corners of society: Katie Mulrey (associate professor astrophysics at Radboud University), Thijs van den Broek (Management Consultant for Societal Issues at Andersson Elffers Felix) and Dorine Schenk (science journalist NTvN, NRC, New Scientist) discuss the connection between their study and their working life and what role physics plays in it. 

This session has been organized by student's association Marie Curie.

Right next to De Vasim is the Waal Energy Industrial Park, formerly the site of the Gelderland Power Plant. Today, it is a place for activities related to sustainable (wind, sun and hydrogen) energy and logistics and water-related industries. Join this excursion for a tour of the park with its developers.

The Nobel Prize in Physics 2025 was awarded to John Clarke, Michel Devoret and John Martinis for the discovery of macroscopic quantum mechanical tunneling and energy quantisation in an electrical circuit.

In this talk, Hans Hilgenkamp (University of Twente) will introduce the concept of macroscopic quantum tunneling and place this in a historical context.  The groundbreaking experiments performed by Clarke, Devoret and Martinis at the University of California Berkeley in the mid 1980's will be described.

These experiments have paved the way for the 'transmon qubit', that operates based on the energy quantisation in a superconducting resonator structure. The most advanced quantum computers currently in development are based on this type of qubit.

In addition to the scientific content, Hilgenkamp will introduce the laurates, their paths to the prize-winning discoveries and their subsequent career steps.