Characterizing electron orbitals and paramagnons in Pr_xY_1-xBa₂Cu₃O₇ using inelastic X-ray scattering

Inelastic X-ray scattering (IXS) has emerged as a powerful experimental technique for investigating the exotic phases arising from strong electron-electron interactions in highly correlated materials. Compared to more traditional elastic X-ray scattering methods, IXS is able to discriminate scattered photon energies, allowing specific excitations to be independently probed. Non-resonant IXS was used to image the Cu 3d_x²-y² and 3d_z² orbitals within the CuO₂ planes of Pr_0.8Y_0.2Ba₂Cu₃O₇ and compared to the parent compound, YBa₂Cu₃O₇, revealing noticeable differences in the in-plane versus out-of-plane orbital structure. Additionally, resonant IXS was used to measure paramagon hardening as a function of praseodymium content in Pr_xY_1-xBa₂Cu₃O₇. This experiment demonstrates the versatility of IXS and its ability to probe a variety of phenomena in highly correlated materials, from imaging static electron orbitals to characterizing dynamic lattice excitations.