Discovery of a New Type of Magnetism Generated by Atomic-Scale Current Loops: Microscopic Evidence for Loop Current Order in a Kagome Metal

A research team has obtained microscopic evidence for a new magnetic state generated by atomic-scale loops of electric current in the kagome metal CsV₃Sb₅. Such a state has long been theoretically proposed, but direct experimental evidence has remained elusive because the associated currents and magnetic fields are extremely small.
Using nuclear quadrupole resonance and nuclear magnetic resonance measurements, the team detected tiny internal magnetic fields in CsV₃Sb₅ and identified them as evidence of loop current order, in which electrons spontaneously circulate on the crystal lattice. This state is understood as an imaginary charge density wave, a new quantum state in which the flow of electrons becomes ordered, in contrast to a conventional charge density wave, where the electron density periodically increases and decreases. These results advance our understanding of hidden electronic orders in quantum materials.

Local magnetic fields generated by atomic-scale current loops

Papers
Journal: Nature Physics
Title: Microscopic signatures of an imaginary charge density wave in a kagome metal
Authors: S. Suetsugu, F. Hori, M. Shibata, S. Kitagawa, K. Ishida, T. Asaba, S. Nakazawa, Q. Li, H. -H. Wen, T. Shibauchi, H. Kontani, and Y. Matsuda
DOI: 10.1038/s41567-026-03339-8