Universality of Low-Energy Mass Renormalization in the Superconducting State of Hole-Doped High-T_c Superconductors

Abstract

We have performed high-resolution angle-resolved photoemission spectroscopy on high-T_c superconductors La_1.85Sr_0.15CuO₄ (LSCO) and Bi₂Sr₂CaCu₂O_8+δ (Bi2212) to study the universality of many-body interaction in hole-doped high-T_c superconductors. We found that the emergence of kink in the dispersion in the off-nodal region at the superconducting state is a common feature, while the energy scale of kink is remarkably different between LSCO and Bi2212. We conclude that the coupling of electrons with spin excitations at the off-nodal region is universal in hole-doped high-T_c cuprates.