Quasiparticle relaxation dynamics in spin-density-wave and superconducting SmFeAsO1−xFx single crystals
T. Mertelj, P. Kusar, V. V. Kabanov, L. Stojchevska, N. D. Zhigadlo, S. Katrych, Z. Bukowski, J. Karpinski, S. Weyeneth, D. Mihailovic
DOI 10.1103/PhysRevB.81.224504 · Physical Review B
Active bibliographic source — not scientific approval
Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.
Abstract
We investigate the quasiparticle (QP) relaxation and low-energy electronic structure in undoped SmFeAsO and near-optimally doped SmFeAsO0.8F0.2 single crystals–exhibiting spin-density wave (SDW) ordering and superconductivity, respectively–using pump-probe femtosecond spectroscopy. In the undoped single crystals a single relaxation process is observed, showing a remarkable critical slowing down of the QP relaxation dynamics at the SDW transition temperature TSDW≃125 K. In the superconducting (SC) crystals multiple relaxation processes are present with distinct SC-state quasiparticle recombination dynamics exhibiting a BCS-like T-dependent superconducting gap, and a pseudogap (PG)-like feature with an onset above 180 K indicating the existence of a pseudogap of magnitude 2ΔPG≃120 meV above Tc. From the pump-photon energy dependence we conclude that the SC state and PG relaxation channels are independent, implying the presence of two separate electronic subsystems. We discuss the data in terms of spatial inhomogeneity and multiband scenarios, finding that the latter is more consistent with the present data.
Source-reported materials — not catalogue approval
| Formula | Reported Tc (K) | Pressure (GPa) | Type |
|---|---|---|---|
| SmFeAsO0.8F0.2 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | — | Pressure not reported | unknown |
Similar papers
Flux pinning in PrFeAsO0.9 and NdFeAsO0.9F0.1 superconducting crystals
similarity 0.93C. J. van der Beek et al.
Source status unknown — claims are unverified
Quasiparticle relaxation dynamics in spin-density-wave and superconducting SmFeAsO_{1-x}F_{x} single crystals
similarity 0.92T. Mertelj et al. · 2010 · arXiv:1001.1047
Source status unknown — claims are unverified
Evidence for a Nodal Energy Gap in the Iron-Pnictide Superconductor LaFePO from Penetration Depth Measurements by Scanning SQUID Susceptometry
similarity 0.92Clifford W. Hicks et al.
Source status unknown — claims are unverified
High Upper Critical Fields and Evidence of Weak-Link Behavior in Superconducting LaFeAsO1−xFx Thin Films
similarity 0.91S. Haindl et al.
Source status unknown — claims are unverified
Distinct pseudogap and superconducting state quasiparticle relaxation dynamics in near-optimally doped SmFeAsO0.8F0.2 single crystals
similarity 0.90T. Mertelj et al. · 2008 · arXiv:0808.2772
Source status unknown — claims are unverified
Enhancement of low-frequency fluctuations and superconductivity breakdown in Mn-doped La1−yYyFeAsO0.89F0.11 superconductors
similarity 0.90F. Hammerath et al.
Source status unknown — claims are unverified