Ultrafast energy- and momentum-resolved dynamics of magnetic correlations in the photo-doped Mott insulator Sr2IrO4
Source abstract
Abstract
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. Recently, photo-excitation has been used to induce similarly exotic states transiently. 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 Néel 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.
Source: europepmc · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Advanced Condensed Matter Physics · Physics of Superconductivity and Magnetism · Magnetic and transport properties of perovskites and related materials
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (34)
Show source-provided references
1. Scalapino, D. J. A common thread: the pairing interaction for unconventional superconductors. Rev. Mod. Phys. 84, 1383–1417 (2012).10.1103/RevModPhys.84.1383 ↗
2. Kim, Y. et al. Fermi arcs in a doped pseudospin-1/2 Heisenberg antiferromagnet. Science 345, 187–190 (2014).10.1126/science.1251151 ↗
3. Cao, Y. et al. Hallmarks of the Mott-metal crossover in the hole doped pseudospin-1/2 Mott insulator Sr2IrO4 . Nature Commun. 7, 11367 (2016).10.1038/ncomms11367 ↗
4. de la Torre, A. et al. Collapse of the Mott gap and emergence of a nodal liquid in lightly doped Sr2IrO4 . Phys. Rev. Lett. 115, 176402 (2015).10.1103/PhysRevLett.115.176402 ↗
5. Fausti, D. et al. Light-induced superconductivity in a stripe-ordered cuprate. Science 331, 189–191 (2011).10.1126/science.1197294 ↗
6. Zhang, J. & Averitt, R. Dynamics and control in complex transition metal oxides. Annu. Rev. Mater. Res. 44, 19–43 (2014).10.1146/annurev-matsci-070813-113258 ↗
7. Aoki, H. et al. Nonequilibrium dynamical mean-field theory and its applications. Rev. Mod. Phys. 86, 779–837 (2014).10.1103/RevModPhys.86.779 ↗
8. Kim, B. J. et al. Phase-sensitive observation of a spin-orbital Mott state in Sr2IrO4 . Science 323, 1329–1332 (2009).10.1126/science.1167106 ↗
9. Kim, J. et al. Magnetic excitation spectra of Sr2IrO4 probed by resonant inelastic X-ray scattering: establishing links to cuprate superconductors. Phys. Rev. Lett. 108, 177003 (2012).10.1103/PhysRevLett.108.177003 ↗
10. Lee, P. A., Nagaosa, N. & Wen, X.-G. Doping a Mott insulator: physics of high-temperature superconductivity. Rev. Mod. Phys. 78, 17–85 (2006).10.1103/RevModPhys.78.17 ↗
11. Wang, F. & Senthil, T. Twisted Hubbard model for Sr2IrO4: magnetism and possible high temperature superconductivity. Phys. Rev. Lett. 106, 136402 (2011).10.1103/PhysRevLett.106.136402 ↗
12. Yan, Y. J. et al. Electron-doped Sr2IrO4: an analogue of hole-doped cuprate superconductors demonstrated by scanning tunneling microscopy. Phys. Rev. X 5, 041018 (2015).
13. Cao, G., Bolivar, J., McCall, S., Crow, J. E. & Guertin, R. P. Weak ferromagnetism, metal-to-nonmetal transition, and negative differential resistivity in single-crystal Sr2IrO4 . Phys. Rev. B 57, R11039–R11042 (1998).10.1103/PhysRevB.57.R11039 ↗
14. Moon, S. J. et al. Electronic structures of layered perovskite Sr2MO4 (M = Ru, Rh, and Ir). Phys. Rev. B 74, 113104 (2006).10.1103/PhysRevB.74.113104 ↗
15. Ehrke, H. et al. Photoinduced melting of antiferromagnetic order in La0.5Sr1.5MnO4 measured using ultrafast resonant soft X-ray diffraction. Phys. Rev. Lett. 106, 217401 (2011).10.1103/PhysRevLett.106.217401 ↗
16. Zhou, S. et al. Glass-like recovery of antiferromagnetic spin ordering in a photo-excited manganite Pr0.7Ca0.3MnO3 . Sci. Rep. 4, 4050 (2014).10.1038/srep04050 ↗
17. Chuang, Y. D. et al. Real-time manifestation of strongly coupled spin and charge order parameters in stripe-ordered La1.75Sr0.25NiO4 nickelate crystals using time-resolved resonant X-ray diffraction. Phys. Rev. Lett. 110, 127404 (2013).10.1103/PhysRevLett.110.127404 ↗
18. Caviglia, A. D. et al. Photoinduced melting of magnetic order in the correlated electron insulator NdNiO3 . Phys. Rev. B 88, 220401 (2013).10.1103/PhysRevB.88.220401 ↗
19. Lee, W.-S. et al. Phase fluctuations and the absence of topological defects in a photo-excited charge-ordered nickelate. Nature Commun. 3, 838 (2012).10.1038/ncomms1837 ↗
20. Boeglin, C. et al. Distinguishing the ultrafast dynamics of spin and orbital moments in solids. Nature 465, 458–461 (2010).10.1038/nature09070 ↗
21. Kampfrath, T. et al. Coherent terahertz control of antiferromagnetic spin waves. Nature Photon. 5, 31–34 (2011).10.1038/nphoton.2010.259 ↗
22. Malinowski, G. et al. Control of speed and efficiency of ultrafast demagnetization by direct transfer of spin angular momentum. Nature Phys. 4, 855–858 (2008).10.1038/nphys1092 ↗
23. Ament, L. J. P., vanVeenendaal, M., Devereaux, T. P., Hill, J. P. & van den Brink, J. Resonant inelastic X-ray scattering studies of elementary excitations. Rev. Mod. Phys. 83, 705–767 (2011).10.1103/RevModPhys.83.705 ↗
24. Dean, M. P. M. Insights into the high temperature superconducting cuprates from resonant inelastic X-ray scattering. J. Magn. Magn. Mater. 376, 3–13 (2015).10.1016/j.jmmm.2014.03.057 ↗
25. Batignani, G. et al. Probing ultrafast photo-induced dynamics of the exchange energy in a Heisenberg antiferromagnet. Nature Photon. 9, 506–510 (2015).10.1038/nphoton.2015.121 ↗
26. Ishii, K. et al. Momentum-resolved electronic excitations in the Mott insulator Sr2IrO4 studied by resonant inelastic X-ray scattering. Phys. Rev. B 83, 115121 (2011).10.1103/PhysRevB.83.115121 ↗
27. Kim, J. et al. Excitonic quasiparticles in a spin–orbit Mott insulator. Nature Commun. 5, 4453 (2014).10.1038/ncomms5453 ↗
28. Okamoto, H. et al. Ultrafast charge dynamics in photoexcited Nd2CuO4 and La2CuO4 cuprate compounds investigated by femtosecond absorption spectroscopy. Phys. Rev. B 82, 060513 (2010).10.1103/PhysRevB.82.060513 ↗
29. Manousakis, E. The spin-1/2 Heisenberg antiferromagnet on a square lattice and its application to the cuprous oxides. Rev. Mod. Phys. 63, 1–62 (1991).10.1103/RevModPhys.63.1 ↗
30. Rønnow, H. M. et al. Spin dynamics of the 2d spin quantum antiferromagnet copper deuteroformate tetradeuterate (CFTD). Phys. Rev. Lett. 87, 037202 (2001).10.1103/PhysRevLett.87.037202 ↗
31. Fujiyama, S. et al. Two-dimensional Heisenberg behavior of Jeff = 1/2 isospins in the paramagnetic state of the spin-orbital Mott insulator Sr2IrO4 . Phys. Rev. Lett. 108, 247212 (2012).10.1103/PhysRevLett.108.247212 ↗
32. Vale, J. G. et al. Importance of XY anisotropy in Sr2IrO4 revealed by magnetic critical scattering experiments. Phys. Rev. B 92, 020406 (2015).10.1103/PhysRevB.92.020406 ↗
33. Rayan Serrao, C. et al. Epitaxy-distorted spin-orbit Mott insulator in Sr2IrO4 thin films. Phys. Rev. B 87, 085121 (2013).10.1103/PhysRevB.87.085121 ↗
34. Chollet, M. et al. The X-ray pump-probe instrument at the LINAC coherent light source. J. Synchrotron Radiat. 22, 503–507 (2015).10.1107/S1600577515005135 ↗