Resonant inelastic X-ray scattering study of charge excitations in superconducting and nonsuperconducting PrFeAsO

Jarrige, I.*; Nomura, Takuji; Ishii, Kenji; Gretarsson, H.*; Kim, Y.-J.*; Kim, J.*; Upton, M.*; Casa, D.*; Gog, T.*; Ishikado, Motoyuki*; et al.

Physical Review B, 86(11), p.115104_1 - 115104_4, 2012/09

https://doi.org/10.1103/PhysRevB.86.115104

We report the first observation by momentum-resolved resonant inelastic X-ray scattering of charge excitations in an iron-based superconductor and its parent compound, PrFeAsO and PrFeAsO respectively, with two main results. First, using calculations based on a 16 band model, we show that the energy of the lowest-lying excitations, identified as interband transitions of dominant , orbital character, exhibits a dramatic dependence on electron correlation. This enables us to estimate the Coulomb repulsion and Hund's coupling , and to highlight the role played by in these peculiar orbital-dependent electron correlation effects. Second, we show that short-range antiferromagnetic correlations, which are a prerequisite to the occurrence of these excitations at the point, are still present in the superconducting state.

Mixed-state Hall effect and flux pinning in Ba(FeCo)As single crystals (x = 0.08 and 0.10)

Wang, L. M.*; Sou, U.-C.*; Yang, H. C.*; Chang, L.-J.; Cheng, C.-M.*; Tsuei, K.-D.*; Su, Y.*; Wolf, T.*; Adelmann, P.*

Physical Review B, 83(13), p.134506_1 - 134506_8, 2011/04

https://doi.org/10.1103/PhysRevB.83.134506

Resonant inelastic X-ray scattering in single-crystal superconducting PrFeAsO

Jarrige, I.; Ishii, Kenji; Ikeuchi, Kazuhiko*; Yoshida, Masahiro; Ishikado, Motoyuki; Hiraoka, Nozomu*; Tsuei, K.-D.*; Iyo, Akira*; Eisaki, Hiroshi*; Kito, Hijiri*; et al.

no journal, , 

A prerequisite to elucidate the mechanism underlying superconductivity in the iron oxypnictides is an in-depth knowledge of the low-lying electronic excitations. In an attempt to unveil those low-energy excitations, we have performed a resonant inelastic X-ray scattering (RIXS) measurement at the Fe K edge in a single crystal of the underdoped superconductor compound PrFeAsO (Tc = 42 K). We discern a feature centered around 4 eV which is reminiscent of the metal-ligand charge transfer in the cuprates, therefore we are tempted to ascribe it to the charge transfer between Fe 3d and As 4p.