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Ultrafast probes of coherent oscillations in Fe-based superconductors

  • Kim, K.W. (Department of Physics, Chungbuk National University)
  • Received : 2017.03.08
  • Accepted : 2017.03.21
  • Published : 2017.03.31

Abstract

Forefront ultrafast experimental techniques have recently proven their potential as new approaches to understand materials based on non-equilibrium dynamics in the time domain. The time domain approach is useful especially in disentangling complicated coupling among charge, spin and lattice degrees of freedom. Various ultrafast experiments on Fe-based superconductors have observed strong coherent oscillations of an $A_{1g}$ phonon mode of arsenic ions, which shows strong coupling to the electronic and magnetic states. This paper reviews the recent reports of ultrafast studies on Fe-based superconductor with a focus on the coherent oscillations. Experimental results with ultrashort light sources from the terahertz-infrared pulses to the hard X-rays from a free electron laser will be presented.

Keywords

References

  1. K. W. Kim, et al., "Ultrafast transient generation of spin density wave order in the normal state of $BaFe_2As_2$ driven by coherent lattice vibrations," Nat. Mater., vol. 11, pp. 497-501, 2012. https://doi.org/10.1038/nmat3294
  2. S. Gerber, et al., "Direct characterization of photoinduced lattice dynamics in $BaFe_2As_2$," Nat. Commun., vol. 6, p. 7377, 2015. https://doi.org/10.1038/ncomms8377
  3. D. Fausti, et al., "Light-induced superconductivity in a stripe-ordered cuprate," Science, vol. 331, pp. 189-191, 2011. https://doi.org/10.1126/science.1197294
  4. A. Pashkin, et al., "Femtosecond response of quasiparticles and phonons in superconducting $YBa_2Cu_3O_{7-{\delta}}$ studied by wideband terahertz spectroscopy," Phys. Rev. Lett., vol. 105, p. 067001, 2010. https://doi.org/10.1103/PhysRevLett.105.067001
  5. S. Nandi, et al., "Anomalous suppression of the orthorhombic lattice distortion in superconducting $Ba(Fe_{1-x}Co_x)_2As_2$ single crystals," Phys. Rev. Lett., vol. 104, p. 057006, 2010. https://doi.org/10.1103/PhysRevLett.104.057006
  6. A. Drew, et al., "Coexistence of static magnetism and superconductivity in $SmFeAsO_{1-x}F_x$ as revealed by muon spin rotation," Nat. Mater., vol. 8, pp. 310-314, 2009. https://doi.org/10.1038/nmat2396
  7. B. Mansart, et al., "Observation of a coherent optical phonon in the iron pnictide superconductor $Ba(Fe_{1-x}Co_x)_2As_2$ (x=0.06 and 0.08)," Phys. Rev. B, vol. 80, p. 172504, 2009. https://doi.org/10.1103/PhysRevB.80.172504
  8. B. Mansart, et al., "Ultrafast transient response and electron-phonon coupling in the iron-pnictide superconductor $Ba(Fe_{1-x}Co_x)_2As_2$," Phys. Rev. B, vol. 82, p. 024513, 2010. https://doi.org/10.1103/PhysRevB.82.024513
  9. Hiroshi Takahashi, et al., "Coherent optical phonons in the iron oxypnictide $SmFeAsO_{1-x}F_x$ (x=0.075)," J. Phys. Soc. Jap., vol. 80, p. 013707, 2011. https://doi.org/10.1143/JPSJ.80.013707
  10. T. Mertelj, et al., "Quasiparticle relaxation dynamics in spin-density-wave and superconducting $SmFeAsO_{1-x}F_x$ single crystals," Phys. Rev. B, vol. 81, p. 224504, 2010. https://doi.org/10.1103/PhysRevB.81.224504
  11. L. X. Yang, et al., "Ultrafast modulation of the chemical potential in $BaFe_2As_2$ by coherent phonons," Phys. Rev. Lett., vol. 112, p. 207001, 2014. https://doi.org/10.1103/PhysRevLett.112.207001
  12. L. Rettig, et al., "Ultrafast Structural Dynamics of the Fe-Pnictide Parent Compound $BaFe_2As_2$," Phys. Rev. Lett., vol. 114, p. 067402, 2015. https://doi.org/10.1103/PhysRevLett.114.067402
  13. A. S. Mishchenko, et al., "Charge dynamics of doped holes in high Tc cuprate superconductors: A clue from optical conductivity," Phys. Rev. Lett., vol. 100, p. 166401, 2008. https://doi.org/10.1103/PhysRevLett.100.166401
  14. Yunkyu Bang, "Pairing mechanism of heavily electron doped FeSe systems: dynamical tuning of the pairing cutoff energy," New J. Phys., vol.18, p. 113054, 2016. https://doi.org/10.1088/1367-2630/18/11/113054
  15. J. J. Lee, et al., "Interfacial mode coupling as the origin of the enhancement of Tc in FeSe films on SrTiO3," Nature, vol. 515, pp. 245-248, 2014. https://doi.org/10.1038/nature13894
  16. A. Aperis, P. Kotetes, G. Varelogiannis, and P. M. Oppeneer, "Small-q phonon-mediated unconventional superconductivity in the iron pnictides," Phys. Rev. B, vol. 83, p. 092505, 2011. https://doi.org/10.1103/PhysRevB.83.092505
  17. F. Yndurain, "Coupling of magnetic moments with phonons and electron-phonon interaction in $LaFeAsO_{1-x}F_x$," Europhys. Lett., vol. 94, p. 37001, 2011. https://doi.org/10.1209/0295-5075/94/37001
  18. T. Yildirim, "Frustrated magnetic interactions, giant magneto_elastic coupling, and magnetic phonons in iron-pnictides," Physica C, vol. 469, pp. 425-441, 2009. https://doi.org/10.1016/j.physc.2009.03.038
  19. N. A. Garcia-Martinez, et al., "Coupling of the As $A_{1g}$ phonon to magnetism in iron pnictides," Phys. Rev. B, vol. 88, p. 165106, 2013. https://doi.org/10.1103/PhysRevB.88.165106
  20. P. B. Allen, "Theory of thermal relaxation of electrons in metals," Phys. Rev. Lett., vol. 59, pp. 1460-1463, 1987. https://doi.org/10.1103/PhysRevLett.59.1460
  21. L. Rettig, et al., "Electron-phonon coupling in 122 Fe pnictides analyzed by femtosecond time-resolved photoemission," New J. Phys., vol. 15, p. 083023, 2013. https://doi.org/10.1088/1367-2630/15/8/083023
  22. L. Rettig, et al., "Ultrafast structural dynamics of the orthorhombic distortion in the Fe-pnictide parent compound $BaFe_2As_2$," Struct. Dyn., vol. 3, p.023611, 2016. https://doi.org/10.1063/1.4947250

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