Multiple bosonic mode coupling in the charge dynamics of the electron-doped superconductor (Pr${}_{2-x}$Ce${}_x$)CuO${}_4$

Abstract

We analyze optical spectroscopy data of the electron-doped superconductor (Pr${}_{2-x}$Ce${}_x$)CuO${}_4$ (PCCO) to investigate the coupling of the charge carriers to bosonic modes. The method of analysis is the inversion of the optical scattering rate ${\tau }_{\mathrm{op}}^{-1}(\omega ,T)$ at different temperatures $T$ by means of maximum entropy technique combined with Eliashberg theory. We find that in the superconducting state the charge carriers couple to two dominant modes one at $\sim 10$meV and a second one at $\sim 45$meV. The low energy mode shows a strong temperature dependence and disappears at or slightly above the critical temperature $T_c$. The high energy mode exists above $T_c$ and moves towards higher energies with increasing temperatures. It also becomes less prominent at temperatures $>100$K above which it evolves into a typical spin-fluctuation background. In contrast to the hole-doped High-$T_c$ superconductors PCCO proves to be a superconductor close to the dirty limit.

10 pages, 8 figures submitted to Physical Review B

References in corpus (1)

• A distinct bosonic mode in an electron-doped high-transition-temperature superconductor