Time-Resolved Optical Reflectivity of the Electron-Doped Nd2−xCexCuO4+δ Cuprate Superconductor: Evidence for an Interplay between Competing Orders

Abstract

We use pump-probe spectroscopy to measure the photoinduced reflectivity ΔR of the electron-doped cuprate superconductor Nd2−xCexCuO4+δ at a value of x near optimal doping, as a function of time, temperature, and laser fluence. We observe the onset of a negative ΔR signal at T*≈75 K, above the superconducting transition temperature, Tc, of 23 K. The relatively slow decay of ΔR, compared to the analogous signal in hole doped compounds, allows us to resolve time-temperature scaling consistent with critical fluctuations. A positive ΔR signal onsets at Tc that we associate with superconducting order. We find that the two signals are strongly coupled below Tc, in a manner that suggests a repulsive interaction between superconductivity and another fluctuating order.

Source-reported materials — not catalogue approval

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