Coexistence of insulator-like paramagnon and metallic spin-orbit exciton modes in SrIrO3

作     者：Paris, Eugenio Zhang, W. Tseng, Y. Efimenko, A. Sahle, C. Strocov, V.N. Skoropata, E. Rolfs, K. Shang, T. Lyu, J. Pomjakushina, E. Medarde, M. Rønnow, H.M. Normand, B. Radovic, M. Schmitt, T. 

作者机构：PSI Center for Photon Sciences Villigen-PSI CH-5232 Switzerland European Synchrotron Radiation Facility 71 Avenue des Martyrs Grenoble38043 France PSI Center for Neutron and Muon Sciences Villigen-PSI CH-5232 Switzerland  School of Physics and Electronic Science East China Normal University Shanghai200241 China CAS Key Laboratory of Magnetic Materials and Devices Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences Ningbo315201 China  LausanneCH-1015 Switzerland PSI Center for Scientific Computing Theory and Data Villigen-PSI CH-5232 Switzerland 

出 版 物：《arXiv》 (arXiv)

年 卷 期：2024年

核心收录：

主　　题：Perovskite 

摘      要：We probe the spectrum of elementary excitations in SrIrO3 by using heterostructured [(SrIrO3)m/(SrTiO3)l] samples to approach the bulk limit. Our resonant inelastic x-ray scattering (RIXS) measurements at the Ir L3-edge reveal a robust low-lying collective magnetic mode with an antiferromagnetic (AF) dispersion similar to the insulators Sr2IrO4 and Sr3Ir2O7, albeit with a large gap and much larger linewidth. At higher energies we find the spin-orbit exciton, also strongly broadened, but with an inverted dispersion and doubled periodicity that are controlled by the charge hopping. These results demonstrate that the AF paramagnon persists, somewhat counterintuitively, far into the metallic regime of the insulator-metal transition driven by the degree of confinement in the heterostructure. We conclude that these two excitations, which are contrasting but coexisting hallmarks of strong AF pseudospin and charge fluctuations in a spin-orbit-coupled Mott-Slater material, are properties intrinsic to the ground state of semimetallic perovskite SrIrO3. © 2024, CC BY.