title: Strong lattice correlation of non-equilibrium quasiparticles in a pseudospin-1/2 Mott insulator Sr2IrO4.
abstract: In correlated oxides the coupling of quasiparticles to other degrees of freedom such as spin and lattice plays critical roles in the emergence of symmetry-breaking quantum ordered states such as high temperature superconductivity. We report a strong lattice coupling of photon-induced quasiparticles in spin-orbital coupling Mott insulator Sr2IrO4 probed via optical excitation. Combining time-resolved x-ray diffraction and optical spectroscopy techniques, we reconstruct a spatiotemporal map of the diffusion of these quasiparticles. Due to the unique electronic configuration of the quasiparticles, the strong lattice correlation is unexpected but extends the similarity between Sr2IrO4 and cuprates to a new dimension of electron-phonon coupling which persists under highly non-equilibrium conditions.
authors.affiliation: Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Yuelin
authors.initials: Y
authors.lastname: Li
authors.affiliation: Center of Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Schaller
authors.affiliation: Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824, USA.
authors.forename: Mengze
authors.initials: M
authors.lastname: Zhu
authors.affiliation: Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Donald A
authors.initials: DA
authors.lastname: Walko
authors.affiliation: Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Jungho
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824, USA.
authors.forename: Xianglin
authors.initials: X
authors.lastname: Ke
authors.affiliation: Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA.
authors.forename: Ludi
authors.initials: L
authors.lastname: Miao
authors.affiliation: Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA.
authors.forename: Z Q
authors.initials: ZQ
authors.lastname: Mao