Theoretical approach to resonant inelastic x-ray scattering in iron-based superconductors at the energy scale of the superconducting gap

Abstract

We develop a phenomenological theory to predict the characteristic features of the momentum-dependent scattering amplitude in resonant inelastic x-ray scattering (RIXS) at the energy scale of the superconducting gap in iron-based superconductors. Taking into account all relevant orbital states as well as their specific content along the Fermi surface we evaluate the charge and spin dynamical structure factors for the compounds LaOFeAs and LiFeAs, based on tight-binding models which are fully consistent with recent angle-resolved photoemission spectroscopy (ARPES) data. We find a characteristic intensity redistribution between charge and spin dynamical structure factors which discriminates between sign-reversing and sign-preserving quasiparticle excitations. Consequently, our results show that RIXS spectra can distinguish between $s_{\pm }$ and $s_{++}$ wave gap functions in the singlet pairing case. In addition, we find that an analogous intensity redistribution at small momenta can reveal the presence of a chiral $p$-wave triplet pairing.

12 pages, 5 figures

References in corpus (18)

• Unconventional pairing originating from disconnected Fermi surfaces in superconducting LaFeAsO${}_{1-x}$F${}_x$}
• High-temperature superconductivity in iron-based materials
• The superconductivity at 18 K in LiFeAs system
• LiFeAs: An Intrinsic FeAs-based Superconductor with Tc = 18K
• A minimal two-band model for the superconducting Fe-pnictides
• Iron-Based Superconductors: current status of materials and pairing mechanism
• How Cooper pairs vanish approaching the Mott insulator in Bi2Sr2CaCu2O8+d
• Theory of magnetic excitations in iron-based layered superconductors
• Neutron scattering as a probe of the Fe-pnicitide superconducting gap
• Spin fluctuations in LiFeAs observed by neutron scattering
• Theory for Magnetism and Triplet Superconductivity in LiFeAs
• Superconductivity from repulsion in LiFeAs: novel s-wave symmetry and potential time-reversal symmetry breaking
• Superconducting gap in LiFeAs from three-dimensional spin-fluctuation pairing calculations
• Neutron scattering study of the oxypnictide superconductor La(O,F)FeAs
• Observation of phonons with resonant inelastic x-ray scattering
• Incommensurate magnetic fluctuations and Fermi surface topology in LiFeAs
• Spin and Orbital Characters of Excitations in Iron Arsenide Superconductors Revealed by Simulated Fe L-Edge RIXS
• Interband Quasiparticle Scattering in Superconducting LiFeAs Reconciles Photoemission and Tunneling Measurements

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• Fluctuations and pairing in Fe-based superconductors: Light scattering experiments
• Superconducting pairing in resonant inelastic X-ray scattering
• Numerical study of resonant inelastic X-ray scattering at the oxygen $K$-edge in insulating cuprates
• Detecting Crystallographic Lattice Chirality using Resonant Inelastic X-ray Scattering