Topological metal-insulator transition within the ferromagnetic state
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 K<sub>2</sub>Cr<sub>8</sub>O<sub>16</sub> 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.
Authors
- A. M. dos Santos (ORCID: https://orcid.org/0000-0001-6900-0816)
- D. G. Mazzone (ORCID: https://orcid.org/0000-0002-0421-0625)
- Konstantinos Papadopoulos (ORCID: https://orcid.org/0000-0003-2661-3262)
- Martin Må̊nsson (ORCID: https://orcid.org/0000-0002-3086-9642)
- Moritz M. Hirschmann (ORCID: https://orcid.org/0000-0003-0610-4612)
- J. Chang (ORCID: https://orcid.org/0000-0002-4655-1516)
- Deepak John Mukkattukavil (ORCID: https://orcid.org/0000-0003-1311-7358)
- Jun Sugiyama (ORCID: https://orcid.org/0000-0002-0916-5333)
- Nami Matsubara (ORCID: https://orcid.org/0000-0002-8324-710X)
- N. Gauthier (ORCID: https://orcid.org/0000-0001-6147-243X)
- Chin Shen Ong (ORCID: https://orcid.org/0000-0001-8747-1849)
- Masahiko Isobe (ORCID: https://orcid.org/0000-0002-9253-7256)
- Olle Eriksson (ORCID: https://orcid.org/0000-0001-5111-1374)
- Masafumi Horio (ORCID: https://orcid.org/0000-0003-2669-5368)
- Hiroshi Uchiyama (ORCID: https://orcid.org/0000-0001-8138-9393)
- Ola Kenji Forslund (ORCID: https://orcid.org/0000-0001-8879-7875)
- Christian Tzschaschel (ORCID: https://orcid.org/0000-0003-3890-8121)
- Kazuya Kamazawa (ORCID: https://orcid.org/0000-0001-7850-9665)
- Yasmine Sassa (ORCID: https://orcid.org/0000-0003-1416-5642)
- Romain Sibille (ORCID: https://orcid.org/0000-0001-6360-7262)
- Hidenori Takagi
- Kazuhiko Ikeuchi (ORCID: https://orcid.org/0000-0003-3351-9354)
- Elisabetta Nocerino (ORCID: https://orcid.org/0000-0003-4441-8882)
Institutions
- Uppsala University (SE)
- Oak Ridge National Laboratory (US)
- High Energy Accelerator Research Organization (JP)
- Stockholm University (SE)
- University of Zurich (CH)
- Institut National de la Recherche Scientifique (CA)
- Max Planck Institute for Solid State Research (DE)
- SPring-8 (JP)
- Japan Synchrotron Radiation Research Institute (JP)
- RIKEN Center for Emergent Matter Science (JP)
- Comprehensive Research Organization for Science and Society (JP)
- Chalmers University of Technology (SE)
- KTH Royal Institute of Technology (SE)
Publication Details
- Journal
- Nature Communications
- Published
- 2026-02-27
- DOI
- https://doi.org/10.1038/s41467-026-70042-w
- Primary Topic
- Topological Materials and Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- U.S. Department of Energy
- Deutsche Forschungsgemeinschaft
- Stiftelsen för Strategisk Forskning
- Knut och Alice Wallenbergs Stiftelse
- Paul Scherrer Institut
- Vetenskapsrådet
- Uppsala Universitet
- Office of Science
- Japan Society for the Promotion of Science
- RIKEN
- Oak Ridge National Laboratory