Abstract
Altermagnets represent a new class of magnetic phases without net magnetization, invariant under a combination of rotation and time reversal. Unlike conventional collinear antiferromagnets (AFM), altermagnets could lead to new correlated states and important material properties deriving from their nonrelativistic spin-split band structure. Indeed, they serve as the magnetic analogue of unconventional superconductors and can yield spin-polarized electrical currents in the absence of external magnetic fields, making them promising candidates for next-generation spintronics. Here, we report altermagnetism in the correlated insulator, magnetically ordered tetragonal oxychalcogenide, La2O3Mn2Se2. Symmetry analysis reveals a dx2-y2-wave-like spin-momentum locking arising from the Mn2O Lieb lattice, supported by density functional theory (DFT) calculations. Magnetic measurements confirm the AFM transition below ∼166K while neutron pair distribution function analysis reveals a 2D short-range magnetic order that persists above the Néel temperature. Single crystals are grown and characterized using x-ray diffraction, optical and electron microscopy, and micro-Raman spectroscopy to confirm the crystal structure, stoichiometry, and uniformity. Our findings establish La2O3Mn2Se2 as a model altermagnetic system realized on a Lieb lattice.
| Original language | English |
|---|---|
| Article number | 024402 |
| Journal | Physical Review Materials |
| Volume | 9 |
| Issue number | 2 |
| DOIs | |
| State | Published - Feb 2025 |
Funding
ACKNOWLEDGMENTS We thank I. Mazin for the fruitful discussions. C.-C.W. and H.J. are supported by an NSF Career Grant No. 2145832. X.L. and F.L. acknowledge financial support from the DOE-BES (Grant No. DE-FG02-04ER46148). Computational resources for this work were supported by CHPC of the University of Utah and the DOE-NERSC. The atomic and magnetic pair distribution function analysis performed by S.R.H. and B.A.F. was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences (DOE-BES) through Award No. DE-SC0021134. The neutron scattering experiments used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. X.H. and T.T.T. thank the NSF (Awards No. NSF-OIA-2227933 and No. NSF-DMR-2338014) and the Arnold and Mabel Backman Foundation (2023 BYI Grant) for the support. The Air Force Office of Scientific Research supported R.M.F. (phenomenological model) under Award No. FA9550-21-1\u20130423 as well as B.S., K.M.K., and K.S.B. (Raman measurements and analysis) under Award No. FA9550-24-1\u20130110. L.Z. acknowledges the support by the NSF CAREER Grant No. DMR-174774 and Alfred P. Sloan Foundation. We thank I. Mazin for the fruitful discussions. C.-C.W. and H.J. are supported by an NSF Career Grant No. 2145832. X.L. and F.L. acknowledge financial support from the DOE-BES (Grant No. DE-FG02-04ER46148). Computational resources for this work were supported by CHPC of the University of Utah and the DOE-NERSC. The atomic and magnetic pair distribution function analysis performed by S.R.H. and B.A.F. was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences (DOE-BES) through Award No. DE-SC0021134. The neutron scattering experiments used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. X.H. and T.T.T. thank the NSF (Awards No. NSF-OIA-2227933 and No. NSF-DMR-2338014) and the Arnold and Mabel Backman Foundation (2023 BYI Grant) for the support. The Air Force Office of Scientific Research supported R.M.F. (phenomenological model) under Award No. FA9550-21-1\u20130423 as well as B.S., K.M.K., and K.S.B. (Raman measurements and analysis) under Award No. FA9550-24-1\u20130110. L.Z. acknowledges the support by the NSF CAREER Grant No. DMR-174774 and Alfred P. Sloan Foundation.