| Abstract: |
From almost the time of its discovery, high temperature superconductivity has been attributed by theorists to magnetic interactions. However, because of difficulties controlling such interactions, and measuring them in superconducting samples, hard experimental evidence (or counter-evidence) has been elusive. Over the past several years, a superconducting material system Ca-La-Ba-Cu-O (CLBLCO) has been developed, that allows tuning of the magnetic interaction with minimal complicating effects. In this talk, we focus on applying a relatively new measurement technique, resonant inelastic x-ray scattering (RIXS), which has shown promise in measuring magnetic interactions even in doped samples. Furthermore, the technique is sensitive to orbital excitations, and also excitations across the charge transfer and Hubbard gaps depending on the resonance selected. Using RIXS, we measure the propagation of spin waves and electronic excitations in CLBCO. This allows us to clarify quantitatively the relation between superconducting transition temperature and spin-spin and/or other interactions which govern these excitations. |