Abstract
We examine coherent phonons in a strongly driven sample of optimally-doped high temperature superconductor . We observe a nonlinear lattice response of the 4.5 THz copper-oxygen vibrational mode at high excitation densities, evidenced by the observation of the phonon third harmonic and indicating the mode is strongly anharmonic. In addition, we observe how high-amplitude phonon vibrations modify the position of the electronic charge transfer resonance. Both of these results have important implications for possible phonon-driven nonequilibrium superconductivity.
- Received 21 February 2019
- Revised 24 September 2019
DOI:https://doi.org/10.1103/PhysRevB.100.184302
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