Probing the Lattice Anharmonicity of Superconducting YBa${}_2$Cu${}_3$O${}_{7-\delta }$ Via Phonon Harmonics

Alberto Ramos-Alvarez, Nina Fleischmann, Luciana Vidas +3

We examine coherent phonons in a strongly driven sample of optimally-doped high temperature superconductor YBa${}_2$Cu${}_3$O${}_{7-\delta }$. We observe a non-linear lattice response of the 4…