Opticcal conductivity spectra σ1(ω) of Nd2-xCexCuO4 thin films, measured by the reflectance-transmittance method (R-T method) which has been proposed to investigate far-infrared spectroscopy, are investigated based on the anisotropic pairing model. Precise measurements of the frequency-dependent conductivity enable us to examine quantitatively the nature of the superconducting gap through infrared properties in the electron-doped high-Tc superconductors. We show that the behavior of optical conductivity σ1 is consistent with the anisotropic superconducting gap and is well explained by the formula for d-wave pairing in the low-energy regime of the far-infrared region. Our results suggest that the electron-doped cuprate superconductors Nd2-xCexCuO4 have nodes in the superconducting gap.
@article{arxiv.cond-mat/0204316,
title = {Anisotropic Optical Conductivity of Nd2-xCexCuO4 Thin Films},
author = {Takashi Yanagisawa and Shigeru Koikegami and Hajime Shibata and Shinji Kimura and Satoshi Kashiwaya and Akihito Sawa and Noritaka Matsubara and Koki Takita},
journal= {arXiv preprint arXiv:cond-mat/0204316},
year = {2015}
}