Details

Autor(en) / Beteiligte

• Hashimoto, K
• Shibauchi, T
• Kasahara, S
• Ikada, K
• Tonegawa, S
• Kato, T
• Okazaki, R
• van der Beek, C J
• Konczykowski, M
• Takeya, H
• Hirata, K
• Terashima, T
• Matsuda, Y

Titel

Microwave surface-impedance measurements of the magnetic penetration depth in single crystal Ba1-xKxFe2As2 superconductors: evidence for a disorder-dependent superfluid density

Ist Teil von

• Physical review letters, 2009-05, Vol.102 (20), p.207001-207001

Ort / Verlag

United States: American Physical Society

Erscheinungsjahr

2009

Link zum Volltext

Quelle

PROLA

Beschreibungen/Notizen

• We report high-sensitivity microwave measurements of the in-plane penetration depth lambda_{ab} and quasiparticle scattering rate 1/tau in several single crystals of the hole-doped Fe-based superconductor Ba(1-x)K(x)Fe(2)As(2) (x approximately 0.55). While a power-law temperature dependence of lambda_{ab} with a power approximately 2 is found in crystals with large 1/tau, we observe an exponential temperature dependence of the superfluid density consistent with the existence of fully opened two gaps in the cleanest crystal we studied. The difference may be a consequence of different levels of disorder inherent in the crystals. We also find a linear relation between the low-temperature scattering rate and the density of quasiparticles, which shows a clear contrast to the case of d-wave cuprate superconductors with nodes in the gap. These results demonstrate intrinsically nodeless order parameters in the Fe arsenides.