Ultrafast energy- and momentum-resolved dynamics of magnetic correlations in the photo-doped Mott insulator Sr2IrO4Dean, M. P. M., Cao, Y., Liu, X., Wall, S., Zhu, D., Mankowsky, R., Thampy, V., Chen, X. M., Vale, J. G., Casa, D., Kim, J., Said, A. H., Juhas, P., Alonso-Mori, R., Glownia, J. M., Robert, A., Robinson, J., Sikorski, M., Song, S., Kozina, M., Lemke, H., Patthey, L., Owada, S., Katayama, T., Yabashi, M., Tanaka, Y., Togashi, T., Liu, J., Serrao, C. R., Kim, B. J., Huber, L., Chang, C. -L., McMorrow, D. F., Foerst, M. & Hill, J. P., Jun-2016, In : Nature Materials. 15, 6, p. 601-606 6 p.
Research output: Contribution to journal › Article › Academic › peer-review
Measuring how the magnetic correlations evolve in doped Mott insulators has greatly improved our understanding of the pseudogap, non-Fermi liquids and high-temperature superconductivity(1-4). Recently, photo-excitation has been used to induce similarly exotic states transiently(5-7). However, the lack of available probes of magnetic correlations in the time domain hinders our understanding of these photo-induced states and how they could be controlled. Here, we implement magnetic resonant inelastic X-ray scattering at a free-electron laser to directly determine the magnetic dynamics after photo-doping the Mott insulator Sr2IrO4. We find that the non-equilibrium state, 2 ps after the excitation, exhibits strongly suppressed long-range magnetic order, but hosts photo-carriers that induce strong, non-thermal magnetic correlations. These two-dimensional (2D) in-plane Neel correlations recover within a few picoseconds, whereas the three-dimensional (3D) long-range magnetic order restores on a fluence-dependent timescale of a few hundred picoseconds. The marked difference in these two timescales implies that the dimensionality of magnetic correlations is vital for our understanding of ultrafast magnetic dynamics.
|Number of pages||6|
|Publication status||Published - Jun-2016|
- X-RAY-SCATTERING, HEISENBERG-ANTIFERROMAGNET, SPIN, SUPERCONDUCTIVITY, OXIDES