Energy dependence of the electron-boson coupling strength in the electron-doped cuprate superconductor Pr1.85Ce0.15CuO4−δ
Physical review B
We studied the superconducting (SC) state depletion process in an electron doped cuprate Pr_1.85Ce_0.15CuO_4-δ by pumping with near-infrared (NIR) and narrow-band THz pulses. When pumping with THz pulses tuned just above the SC gap, we find the absorbed energy density required to deplete superconductivity, A_dep, matches the thermodynamic condensation energy. Contrary, by NIR pumping A_dep is an order of magnitude higher, despite the fact that the SC gap is much smaller than the energy of
... nt bosonic excitations. The result implies that only a small subset of bosons contribute to pairing.