Quasiparticle dynamics in overdoped Bi1.4Pb0.7Sr1.9CaCu2O8+δ: Coexistence of superconducting gap and pseudogap below Tc

Authors: Saritha K. Nair, Xingquan Zou, Elbert E. M. Chia, Jian-Xin Zhu, C. Panagopoulos, S. Ishida and S. Uchida

Published in: Physical Review B 82, 212503, 2010.

Photoexcited quasiparticle relaxation dynamics in overdoped Bi1.4Pb0.7Sr1.9CaCu2O8+δ (Tc =65  K, hole doping p=0.22) single crystal is investigated as a function of temperature. We provide evidence of a ~22  meV pseudogap (T*≈100  K) at this doping level. Moreover, this pseudogap vanishes at T*. Our data support the scenario where both the superconducting gap and pseudogap coexist in the superconducting state. Our results also suggest an increased scattering rate between electrons and spin fluctuations as the sample enters the pseudogap phase.

DOI: 10.1103/PhysRevB.82.212503