Strong-coupling effects in cuprate high-T_c superconductors by magneto-optical studies

摘要

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 YBa_2Cu_3O_y, (YBCO). Infrared data are directly compared with earlier inelastic neutron scattering results by Dai et al. [Nature (London) 406, 965 (2000)] revealing a characteristic depression of the magnetic resonance in H‖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.