HFML-FELIX at NWO Physics 2026: Exploring Matter Under Extreme Conditions

Last week, the Dutch physics community gathered for NWO Physics 2026, a major national conference that offers a broad overview of current physics research in the Netherlands. Traditionally, the conference provides a platform where early-career researchers present their work alongside leading national and international scientists. This year’s theme, EXPLORE, highlighted the idea that new discoveries and breakthroughs in physics are driven by exploration—pushing boundaries and investigating the unknown. Against this backdrop, HFML-FELIX was strongly represented with five scientific contributions, reflecting the breadth of expertise within our laboratory.

Our director, Marc Baldus, delivered an invited talk in the focus session ‘A National Research Infrastructure for Science Under Extreme Conditions’. The presentation introduced HFML-FELIX as a newly established NWO-I institute and highlighted its strategic role within the Dutch research landscape. Marc Baldus emphasized howour institute investigates the fundamental properties of matter under extreme conditions, combining strong magnetic fields and intense free-electron laser radiation. As part of a national consortium, HFML-FELIX brings together world-unique infrastructure with advanced experimental, theoretical, and computational expertise to address major scientific challenges and support future national research initiatives.

Recent research

Elvina Dilmieva, Research Officer at HFML-FELIX, gave an invited talk in the focus session ‘Caloric materials for cooling technologies.’ Her presentation focused on newly developed experimental methodologies for studying magnetocaloric materials in high magnetic fields. The talk attracted significant interest from external users of the laboratory, highlighting the relevance of our facilities for applied and fundamental research in sustainable cooling technologies and opening new opportunities for collaboration.

Postdoc Marius Gerlach of the FELIX Infrared and THz Spectroscopy group, gave a talk in the session ‘Atomic, Molecular and Optical Physics: Molecular physics and spetroscopy’. He explained more about our work on vibronic coupling effects in gas-phase molecular ions of astrochemical interest, using cryogenic ion trapping techniques in combination with the broadband tunable infrared free-electron lasers at our institute.

Strong PhD representation

Our PhD students also made strong contributions to NWO Physics 2026. Chiara Cocchi, from the Correlated Electron Systems group, presented high-field studies on the Weyl semimetal PtBi₂ in the session ‘Topological materials’, revealing new insights into quantum oscillations and the material’s exotic superconducting properties, whose origin remains an open question. Niels Fennema presented recent experiments in the focus session ‘Chirality and angular momentum of crystals’ on chiral phonons that control magnetization in ferrimagnetic GdFeCo films. Using the free-electron laser together with transient grating spectroscopy, he showed that magnetization reversal remains robust under non-ideal ellipticity conditions and that the efficiency of switching reaches a maximum before the pump frequency reaches the phonon resonance mode.

Maarten de Dreu, second-year PhD student at HFML-FELIX, delivered an oral presentation on magnetostructural transitions in frustrated halide double perovskites, exploring the interplay between magnetic interactions and structural phase transitions. All presentations were well received and highlighted the active role of early-career researchers in advancing fundamental materials physics at our lab.

The conference provided a valuable opportunity to exchange ideas, present recent results, and strengthen connections within the Dutch physics community. We look forward to continuing these discussions and collaborations in future meetings.