Laser pulse alters magnetic behavior of a cuprate’s electrons

A femtosecond laser pulse is altering the magnetic behavior of electrons within an electron-doped cuprate superconductor, according to new research. Scientists from the European XFEL in Schenefeld, Germany, collaborated with researchers at Emory University and the Stanford Institute for Materials and Energy Sciences to track collective magnetic excitations, known as paramagnons, after they were driven out-of-equilibrium. The work demonstrates an anti-Stokes signal linked to paramagnon generation, modifying their dispersion near the material's zone center while leaving the bandwidth unchanged. This light-driven boost to the paramagnon population and resulting spectral-weight transfer could provide new methods for manipulating cuprate properties. Time-resolved resonant inelastic X-ray scattering (trRIXS) measurements revealed a modification…