The magnitude and the temperature dependence of the superconducting order parameter {\Delta}(T) of single-crystals of Cd2Re2O7 (Tc = 1.02 K) was measured using point contact spectroscopy. In order to fit the conductance spectra and to extract the order parameter at different temperatures we generalized the Blonder-Tinkham-Klapwijk theory by including the self-energy of the quasiparticles into the Bogoliubov equations. This modification enabled excellent fits of the conductance spectra. {\Delta}(T) increases steeply below the superconducting transition temperature of 1.02 K and levels off below about 0.8 K depending on measurement directions where its value varied from 0.22(1) meV to 0.26(1) meV. Our results indicate the presence of a strong electron-phonon interaction and an enhanced quasiparticle damping and may be related to a possible phase transition within the superconducting region at about 0.8 K.
@article{arxiv.1407.5695,
title = {Quasiparticle-Self-Energy and its Effect on the Superconducting Order Parameter of the Pyrochlore Superconductor Cd2Re2O7},
author = {Fereidoon S Razavi and Yousef Rohanizadegan and Mojtaba Hajialamdari and Maureen Reedyk and Bozidar Mitrović and Reinhard K Kremer},
journal= {arXiv preprint arXiv:1407.5695},
year = {2014}
}