title: Resonant inelastic x-ray scattering as a probe of the phase and excitations of the order parameter of superconductors.
abstract: The capability to probe the dispersion of elementary spin, charge, orbital, and lattice excitations has positioned resonant inelastic x-ray scattering (RIXS) at the forefront of photon science. Here we develop the scattering theory for RIXS on superconductors, calculating its momentum-dependent scattering amplitude. Considering superconductors with different pairing symmetries, we show that the low-energy scattering is strongly affected by the superconducting gap and coherence factors. This establishes RIXS as a tool to disentangle pairing symmetries and to probe the elementary excitations of unconventional superconductors.
authors.affiliation: Institute for Theoretical Solid State Physics, IFW Dresden, D-01069 Dresden, Germany.
authors.forename: Pasquale
authors.initials: P
authors.lastname: Marra
authors.affiliation: Institute for Theoretical Solid State Physics, IFW Dresden, D-01069 Dresden, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Sykora
authors.affiliation: Institute for Theoretical Solid State Physics, IFW Dresden, D-01069 Dresden, Germany.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Wohlfeld
authors.affiliation: Institute for Theoretical Solid State Physics, IFW Dresden, D-01069 Dresden, Germany and Department of Physics, TU Dresden, D-01062 Dresden, Germany.
authors.forename: Jeroen
authors.initials: J
authors.lastname: van den Brink