Unconventional superconductivity observed with Raman spectroscopy in p- and n-type cuprates

We study the electronic Raman spectra of p- and n-type cuprates. In particu lar, we study the electronic continuum and the energy of the 2 Delta peaks that form below T-c as a function of photon polarization (symmetry within t he crystal). In the present work we discuss heavily overdoped Bi2Sr2CaCu2O8 +delta (T-c = 54 K) where the electronic continuum and energy gap are domin ated by excitations of Big symmetry. We compare and contrast this with n-ty pe crystals of Nd1.85Ce0.15CuO4+delta (T-c = 21 K) and Pr1.81Ce0.15CuO4+del ta (T-c = 22 K), where the superconducting 2 Delta peaks are strongest in B -2g symmetry. All three samples show 2 Delta (max) = 4.5k(B)T(c). We discus s our results using red (lambda = 647, 700 nm) excitation wavelengths in th e context of earlier studies performed using higher energy green (lambda = 514.5 nm) and blue (lambda = 476, 488 am) lasers. Published by Elsevier Sci ence B.V.