Details

Autor(en) / Beteiligte

• Umezawa, K
• Li, Y
• Miao, H
• Nakayama, K
• Liu, Z-H
• Richard, P
• Sato, T
• He, J B
• Wang, D-M
• Chen, G F
• Ding, H
• Takahashi, T
• Wang, S-C

Titel

Unconventional anisotropic s-wave superconducting gaps of the LiFeAs iron-pnictide superconductor

Ist Teil von

• Physical review letters, 2012-01, Vol.108 (3), p.037002-037002, Article 037002

Ort / Verlag

United States

Erscheinungsjahr

2012

Quelle

American Physical Society Journals

Beschreibungen/Notizen

• We have performed high-resolution angle-resolved photoemission spectroscopy on Fe-based superconductor LiFeAs (T(c)=18 K). We reveal multiple nodeless superconducting (SC) gaps with 2Δ/k(B)T(c) ratios varying from 2.8 to 6.4, depending on the Fermi surface (FS). We also succeeded in directly observing a gap anisotropy along the FS with magnitude up to ~30%. The anisotropy is fourfold symmetric with an antiphase between the hole and electron FSs, suggesting complex anisotropic interactions for the SC pairing. The observed momentum dependence of the SC gap offers an excellent opportunity to investigate the underlying pairing mechanism.