Tracking the temperature dependence of paramagnons in cuprate supeconductors

Among the others, spin fluctuations are considered as the most promising candidate to mediate the pairing interaction in high Tc superconducting cuprates. The role of spin is nonetheless still debated, particularly as for the interplay with other degrees of freedom. Although high energy paramagnon excitations have been vastly studied in their doping dependence with RIXS, a temperature dependence study across the phase diagram is still missing. In this regard, we hereby propose to perform a full temperature dependence study of YBa2Cu3O7-δ samples at two distinct doping, also exploiting the unique capability of ID32 to measure the scattered photons polarization to disentangle the spin temperature effects to the charge excitations. If successful the experiment will represent the first study of high energy paramagnetic excitations across the superconducting transition in a cuprate superconductor, elucidating further their role in the unconventional pairing of these systems.