Topological metal-insulator transition within the ferromagnetic state
Journal article, 2026
A major challenge in condensed matter physics is integrating topological phenomena with correlated electron physics to leverage both types of states for next-generation quantum devices. Metal-insulator transitions are central to bridging these two domains while simultaneously serving as on-off switches for electronic states. Here, we demonstrate how the prototypical material of K2Cr8O16 undergoes a ferromagnetic metal-insulator transition accompanied by a change in band topology. Through inelastic x-ray and neutron scattering experiments combined with first-principles theoretical calculations, we show that this transition is not driven by a Peierls mechanism, given the lack of phonon softening. Instead, we establish the transition as a topological metal-insulator transition within the ferromagnetic phase with potential axionic properties, where electron correlations play a key role in stabilizing the insulating state. These results reveal how a metal-insulator transition provides a pathway through which magnetism, topology, and electronic correlations interact.
Author
Ola Kenji Forslund
University of Zürich
Uppsala University
Chin Shen Ong
Uppsala University
Moritz M. Hirschmann
RIKEN
Nicolas Gauthier
INRS-Energy, Materials and Telecommunications
Hiroshi Uchiyama
Japan Synchrotron Radiation Research Institute (JASRI)
Christian Tzschaschel
University of Zürich
Daniel G. Mazzone
Paul Scherrer Institut
Romain Sibille
Paul Scherrer Institut
Antonio M. dos Santos
Oak Ridge National Laboratory
M. Horio
University of Zürich
E. Nocerino
Stockholm University
Paul Scherrer Institut
Nami Matsubara
Royal Institute of Technology (KTH)
Deepak John Mukkattukavil
Uppsala University
Konstantinos Papadopoulos
Chalmers, Physics, Materials Physics
Kazuya Kamazawa
Comprehensive Research Organization for Science and Society (CROSS)
Kazuhiko Ikeuchi
Comprehensive Research Organization for Science and Society (CROSS)
High Energy Accelerator Research Organization
H. Takagi
Max Planck Society
Masahiko Isobe
Max Planck Society
Jun Sugiyama
Comprehensive Research Organization for Science and Society (CROSS)
J. Chang
University of Zürich
Yasmine Sassa
Royal Institute of Technology (KTH)
Olle Eriksson
Uppsala University
Martin Månsson
Royal Institute of Technology (KTH)
Nature Communications
2041-1723 (ISSN) 20411723 (eISSN)
Vol. 17 1 2112Subject Categories (SSIF 2025)
Condensed Matter Physics
Other Physics Topics
DOI
10.1038/s41467-026-70042-w
PubMed
41760618