Theoretical approach to direct resonant inelastic x-ray scattering on magnets and superconductors
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. In this work, we will investigate how RIXS can contribute to a deeper understanding of the orbital properties and of the pairing mechanism in unconventional high-temperature superconductors. In particular, we will show how direct RIXS spectra of magnetic excitations can reveal long-range orbital correlations in transition metal compounds, by discriminating different kind of orbital order in magnetic and antiferromagnetic systems. Moreover, we will show how RIXS spectra of quasiparticle excitations in superconductors can measure the superconducting gap magnitude, and reveal the presence of nodal points and phase differences of the superconducting order parameter on the Fermi surface. This can reveal the properties of the underlying pairing mechanism in unconventional superconductors, in particular cuprates and iron pnictides, discriminating between different superconducting order parameter symmetries, such as $s$, $d$ (singlet pairing) and $p$ wave (triplet pairing).
- Pub Date:
- May 2016
- Condensed Matter - Superconductivity;
- Condensed Matter - Strongly Correlated Electrons
- Ph. D. thesis, IFW-Dresden and Technische Universitaet Dresden. Submitted in February 2015, defended in October 2015. Partially based on: arXiv:1405.5556, arXiv:1302.5028, arXiv:1212.0112, and arXiv:1205.4940. Revised version. 132 pages, 30 figures