Strong-coupling Effects in cuprate High-$T_c$ Superconductors by magnetooptical studies

Abstract

Signatures of strong coupling effects in cuprate high-$T_c$ superconductors have been authenticated through a variety of spectroscopic probes. However, the microscopic nature of relevant excitations has not been agreed upon. Here we report on magneto-optical studies of the CuO${}_2$ plane carrier dynamics in a prototypical high-$T_c$ superconductor YBaCu${}_3$O${}_y$ (YBCO). Infrared data are directly compared with earlier inelastic neutron scattering results by Dai \textit{et al}. [Nature (London) \textbf{406}, 965 (2000)] revealing a characteristic depression of the magnetic resonance in H $\parallel$ \textit{c} field less than 7 T. This analysis has allowed us to critically assess the role of magnetic degrees of freedom in producing strong coupling effects for YBCO system.

4 pages, two figures