title: Time-resolved optical reflectivity of the electron-doped Nd(2-x)Ce(x)CuO(4+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 Nd(2-x)Ce(x)CuO(4+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, T(c), 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 T(c) that we associate with superconducting order. We find that the two signals are strongly coupled below T(c), in a manner that suggests a repulsive interaction between superconductivity and another fluctuating order.
authors.affiliation: Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: J P
authors.initials: JP
authors.lastname: Hinton
authors.forename: J D
authors.initials: JD
authors.lastname: Koralek
authors.forename: G
authors.initials: G
authors.lastname: Yu
authors.forename: E M
authors.initials: EM
authors.lastname: Motoyama
authors.forename: Y M
authors.initials: YM
authors.lastname: Lu
authors.forename: A
authors.initials: A
authors.lastname: Vishwanath
authors.forename: M
authors.initials: M
authors.lastname: Greven
authors.forename: J
authors.initials: J
authors.lastname: Orenstein