We use femtosecond spectroscopy to investigate the quasiparticle relaxation and low-energy electronic structure in a nearly optimally doped pnictide superconductor with Tc=49.5K. Multiple relaxation processes are evident, with distinct superconducting state quasiparticle recombination dynamics exhibiting a T-dependent superconducting gap, and a clear "pseudogaplike" feature with an onset above 180 K indicating the existence of a temperature-independent gap of magnitude ΔPG=61±9meV above Tc. Both the superconducting and pseudogap components show saturation as a function of fluence with distinct saturation fluences 4 and 40μJ/cm2, respectively. © 2009 The American Physical Society.
Distinct pseudogap and quasiparticle relaxation dynamics in the superconducting state of nearly optimally doped SmFeAsO0.8F0.2 single crystals
Gadermaier, C.;
2009-01-01
Abstract
We use femtosecond spectroscopy to investigate the quasiparticle relaxation and low-energy electronic structure in a nearly optimally doped pnictide superconductor with Tc=49.5K. Multiple relaxation processes are evident, with distinct superconducting state quasiparticle recombination dynamics exhibiting a T-dependent superconducting gap, and a clear "pseudogaplike" feature with an onset above 180 K indicating the existence of a temperature-independent gap of magnitude ΔPG=61±9meV above Tc. Both the superconducting and pseudogap components show saturation as a function of fluence with distinct saturation fluences 4 and 40μJ/cm2, respectively. © 2009 The American Physical Society.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
