Antiferromagnetic excitonic insulator state in Sr 3 Ir 2 O 7 .

Autor: Mazzone DG; Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, NY, 11973, USA. daniel.mazzone@psi.ch.; Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, CH-5232, Villigen, Switzerland. daniel.mazzone@psi.ch., Shen Y; Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, NY, 11973, USA., Suwa H; Department of Physics, The University of Tokyo, Tokyo, 113-0033, Japan.; Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, 37996, USA., Fabbris G; Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439, USA., Yang J; Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, 37996, USA., Zhang SS; Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, 37996, USA., Miao H; Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA., Sears J; Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, NY, 11973, USA., Jia K; Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China., Shi YG; Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China., Upton MH; Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439, USA., Casa DM; Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439, USA., Liu X; School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China. liuxr@shanghaitec.edu.cn., Liu J; Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, 37996, USA., Batista CD; Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, 37996, USA.; Quantum Condensed Matter Division and Shull-Wollan Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA., Dean MPM; Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, NY, 11973, USA. mdean@bnl.gov.
Jazyk: angličtina
Zdroj: Nature communications [Nat Commun] 2022 Feb 17; Vol. 13 (1), pp. 913. Date of Electronic Publication: 2022 Feb 17.
DOI: 10.1038/s41467-022-28207-w
Abstrakt: Excitonic insulators are usually considered to form via the condensation of a soft charge mode of bound electron-hole pairs. This, however, presumes that the soft exciton is of spin-singlet character. Early theoretical considerations have also predicted a very distinct scenario, in which the condensation of magnetic excitons results in an antiferromagnetic excitonic insulator state. Here we report resonant inelastic x-ray scattering (RIXS) measurements of Sr 3 Ir 2 O 7 . By isolating the longitudinal component of the spectra, we identify a magnetic mode that is well-defined at the magnetic and structural Brillouin zone centers, but which merges with the electronic continuum in between these high symmetry points and which decays upon heating concurrent with a decrease in the material's resistivity. We show that a bilayer Hubbard model, in which electron-hole pairs are bound by exchange interactions, consistently explains all the electronic and magnetic properties of Sr 3 Ir 2 O 7 indicating that this material is a realization of the long-predicted antiferromagnetic excitonic insulator phase.
(© 2022. The Author(s).)
Databáze: MEDLINE
Externí odkaz: