Argonne National Laboratory

Research Highlight | Materials Science

Magnetic Lifshitz transition in a Kagome-Lattice metal
In a study published in Communications Physics, researchers report and investigate a rare magnetization-driven Lifshitz transition in YMn6Sn6.
(a) Magnetoresistance (red line) plotted on top of the magnetic Bragg peak observed in a SANS experiment. (b) Magnetoresistance as a function of magnetization. Arrow marks the LT (c) Band structure showing flat band (bold green) that is responsible for the LT in the spin polarized state. Blue bands are in unmagnetized state (d) Fermi surface in the ferromagnetic state showing the anisotropic hole pocket around L.

Scientific Achievement

We have discovered a rare magnetization-driven Lifshitz transition (LT) in YMn6Sn6 and connect it with the response of a quasi-flat band to magnetic field.

Significance and Impact

Our findings provide a novel example of how magnetism can influence electronic band structure when a sublattice magnetization drives an abrupt change of the Fermi surface topology.

Research Details

  • Large (50%) drop of magnetoresistance (MR) without a change in magnetic structure
  • Magnetic order rearranges band structure to align a flat band at the Fermi level, absent in the unmagnetized state. This is a topological transition without symmetry-breaking, or a Liftshitz transition.
  • Small angle neutron scattering (SANS) verifies no change in magnetic structure at the LT.

DOI: 10.1038/s42005-022-00833-2

Download this highlight

Argonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation’s first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America’s scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science.

The U.S. Department of Energy’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit https://​ener​gy​.gov/​s​c​ience.